Engineering:Benz Patent-Motorwagen

Short description: First modern automobile

Benz Patent-Motorwagen
Overview
Manufacturer	Benz & Cie. Rheinische Gasmotorenfabrik (subsumed within Mercedes-Benz)
Production	1886–1893
Layout	Rear Engine, RWD
Powertrain
Engine	954 cc (58.2 cu in; 1.0 L) single cylinder engine (Ligroin fuel)
Power output	0.68 PS (0.50 kW; 2⁄3 bhp) @ 400 rpm 0.082 kg⋅m (4⁄5 N⋅m; 0.59 lb⋅ft)
Transmission	Single-speed belt drive to counter shaft with differential; then separate chain drives to each rear wheel
Dimensions
Wheelbase	1,450 mm (57.1 in)
Length	2,700 mm (106.3 in)
Width	1,400 mm (55.1 in)
Height	1,450 mm (57.1 in)
|uk|Kerb|Curb}} weight	270 kg (600 lb)
Chronology
Successor	Benz Velo

The Benz Patent-Motorwagen ("patent motorcar") was a belt-driven motor tricycle with a single-cylinder four-stroke engine. It was developed over the period 1884 - 1887 by the German engineer Carl Benz and is widely regarded as the first practical automobile. It was also the first car to be put into production, being manufactured and sold between 1887 and 1893.

The engine's output was stabilised by a flywheel. In the first vehicles this was horizontal and the vehicles had a single-speed belt-drive. Later vehicles had a vertical flywheel and two-speed belt-drives.

Production ceased after Benz had perfected two-wheel steering and began manufacturing four-wheel models from 1893. Around 1895 the Sales Manager at Benz & Cie had parts of the original vehicle sought out and reassembled in a vehicle which evoked the original. It is referred to here as the "reassembled original vehicle".

Motorwagen Nr. 1

Benz began work on his vehicle in 1884 but it was in Spring 1885 that he got his prototype moving under its own power for the first time. He worked continually to improve his vehicle. Initially it would only run for a short distance and was driven only in the factory grounds. Over the year 1885 its range grew, and in the latter part of the year Benz took it out on unfrequented roads and at night.

By the end of 1885 Benz was sufficiently confident in it to prepare a patent application. This was filed on 29 January 1886. and granted on 2 November 1886 (if a patent is granted, the date of the patent is the filing date). The 1885 vehicle is known as Patent-Motorwagen Nr. 1. It is depicted in the patent drawings.

Motorwagen Nr. 2

The engraving captioned Patent-Motorwagen Nr. 2 was used by Benz & Cie in advertising in 1888 without any identification as to what it depicted. It appeared in William Worby Beaumont's 1900 book Motor Vehicles and Motors with the caption "Benz second motor tricycle carriage // Made in 1886, and ran at 10 miles an hour maximum". Worby Beaumont states that it is "from an engraving lent me by Mr. Benz, of the second type of car he made."

The engraving shows a vehicle which has a similar structure and engine to the surviving Patent-Motorwagen in the Science Museum in London including:

• the same type of seat and controls: hand levers on stalks in the middle and a lever outside the frame tube on the left;
• two vertical cylinders (silencer and carburettor) to the left of the sprocket of the rear wheel;
• a horizontal flywheel at the back which barely projects behind the rear wheel.

All of these tie this vehicle to the vehicle in the Science Museum and distinguish it from the vehicle in the patent drawings.

On 4 June 1886 a report appeared in the Neue Badische Landeszeitung which describes a motorised tricycle, including that

In front of [the seat] are the steering and brake levers. By means of another lever, the vehicle is set in motion or stopped at will, by directing the belt, which transmits the motive power of the engine to the wheels, onto the loose or fixed pulley.

This describes the operation of the levers in Model 2 and, we may infer, in the engraving. The hand lever in the centre next to the steering applies the external brakes to the wheels. The lever to the left of the seat does what it did in the patent drawings, but the mechanism is different because the lever has been moved backwards and there is now a single rod which applies the band brake and shifts the belt. In the patent drawings the steering lever is atop a stalk at the right edge and the combined drive/band-brake lever is on the left, outside the tubular frame.

The combination of Benz's statement that the engraving is of his second motor tricycle with the detail about the levers in front of the seat combine to establish that:

• the engraving shows the vehicle which Benz drove around Mannheim in early summer 1886;
• it was Benz's second type of car, hence Patent-Motorwagen Nr. 2;
• Patent-Motorwagen Nr. 2 was the first practical car, not Patent-Motorwagen Nr. 1.

Motorwagen Nr. 2 was far better suited to use on public roads than Nr. 1: it had better brakes; all the controls could be reached by a driver sitting on the left; it had stronger, wooden wheels with iron tyres.

Motorwagen Nr. 3

Two photographs exist showing side and rear views of a vehicle which is intermediate between Nr. 2 and the Science Museum's vehicle. Nr. 2 had a single seat and no suspension at the front. The photograph of the side shows a vehicle very similar to the Science Museum's, with a front rear--facing seat and full suspension. The photograph of the rear reveals signs of welding which suggest that it has been modified from some previous form. The engine is consistent with that depicted in Nr. 2.

In the records of Benz & Cie, there is a Patent-Motorwagen Nr. 3; after this, vehicles have a Fabrikationsnummer (serial number). Nr. 3 is usually identified as the vehicle in a contemporary newspaper illustration in which Benz and his wife Bertha are depicted driving around Munich in September 1888. This vehicle looks very similar to its prototype: the differences lie at the back, where the engine of the prototype is not enclosed behind the seat.

Nr. 1 and Nr. 2 are stages in the development of the Patent-Motorwagen. Nr. 3 is more likely to be the final stage in this development than a production vehicle. The vehicle in these two photographs is referred to in this article as Nr. 3. Benz appears to have used it as his personal car until switching to a new Model 2 around the end of 1887. Around this time, Nr. 3 was scrapped ("disassembled"). Parts which could be reused were salvaged.

As his new car looked identical except at the back, it was natural for people to refer to this vehicle as Nr. 3, even though it was now a production vehicle, not its prototype.

Model 2

Carl and Bertha Benz driving around Munich in their Model 2 Patent-Motorwagen, September 1888

Benz made his first sale of a motor vehicle in 1887 to Émile Roger, a bicycle manufacturer who went on to become his French agent for motor cars. This sale seems to have been semi-private: Roger came to see Benz in Mannheim and Mercedes-Benz date public sale (and therefore production) as having started in 1888. In September 1888 Benz exhibited a vehicle in Munich and was pictured in a newspaper driving around Munich with his wife Bertha. The vehicle in that image matches exactly the Science Museum's and (slightly less well) the photograph used here with the caption Patent-Motorwagen Model 2. It too has a horizontal flywheel which projects slightly behind the rear box. This photograph is Fig. 27 of Benz's Lebensfahrt, a combined memoir and technical history published in 1925. Its caption translates as

My first production car from 1888. 1.5 hp, 2 speeds up to approximately 16 km/h, price at the time 3000 Marks

As the vehicle in the Science Museum has only one speed, the caption appears wrong about the number of speeds. The explanation appears to lie in Benz & Cie's (and now Mercedes-Benz's) practice of regarding all Patent-Motorwagen as Model 3 and ascribing to such vehicles the characteristics of the later, two-speed versions. That this vehicle with the rectangular wooden box was the first production car is confirmed by an advertisement of unknown date which appeared in Britain with the caption "The first petrol motor car".

Worby Beaumont does not depict this vehicle: his next image is that shown here as Patent-Motorwagen Model 3. In it, the body was changed to emphasise the passenger-carrying part and louvres were added to the sides of a smaller rear box. They were the external face of two water tanks / radiators which were added to the coolant system. Given the visible changes to the body, the vehicles with a single large wooden box are identified here as Model 2, while those with louvres are Model 3.

Model 3

The image used here of Model 3 is that in Worby Beaumont. He captions it "Benz third motor carriage // Made in 1888, for running at 12–15 miles an hour". The image is derived from a photograph taken outside the works on Waldhofstrasse in Mannheim which Mercedes-Benz identify as Model 3. The photograph is sufficiently clear to be able to see the vehicle's horizontal flywheel. After feedback from Bertha Benz as a result of her trip in a Model 2 to Pforzheim in August 1888, an extra, low gear was added to the Model 3. This involved adding a second belt-drive for the low gear and changing the flywheel from horizontal to vertical.

As Mercedes-Benz identify all production Patent-Motorwagen as Model 3 and date production from when the vehicle was put on sale to the public, Worby Beaumont's date of 1888 does not tell us when Model 3 was first produced. As Model 2 was exhibited in September 1888, Model 3 is unlikely to have been ready then. It seems likely that Benz was selling the single-speed Model 3 at the Paris Expo in May 1889 and that the two-speed Model 3 with the vertical flywheel superseded it as soon as it was ready.

Sales Numbers

Benz & Cie sold about 25 Patent-Motorwagen between 1887 and 1894. The Benz Viktoria sold to Theodor von Liebieg in 1894 was factory number 76. Benz also supplied vehicles in kit form to French agent Émile Roger, who had sold about 50 of their vehicles (including the Victoria and the Velo) by 1894. The Velo was a runaway success and perhaps 10 of Roger's 50 sales to 1894 could have been these.

In his Lebensfahrt, Benz writes that, despite the absence of Locomotive Acts, he made no sales in Germany for years. That being so, all sales of the Model 2 would have been through Roger. The handful of Model 2's known to have existed may be all that there ever were. Ironically, the Locomotive Acts which suppressed sales in Britain may also have preserved the one Model 2 which found its way there: until 1896 its owner would have needed to keep his head down and use it only locally (if he could keep it in running order when there were no motor mechanics in Britain). By the time it became legal, the Model 2 was obsolescent.

Reassembled Original Vehicle

File:Benz Patent-Motorwagen Nr 1 comparison.jpg

Side views of the Benz Patent-Motorwagen Nr. 1 as in the patent drawing and a modern replica

Around 1895 the Sales Manager at Benz had surviving parts of the original vehicle sought out and reassembled. It was photographed in the late 1890s. In 1906 it was given to the Deutsches Museum in Munich. In 1925 it headed a procession of historic vehicles with Benz at the controls. A video from the 1920s or 1930s shows it being demonstrated. It remains in the Museum today.

When the surviving parts of the original vehicle were reassembled, the aim appears to have been to produce a working demonstrator which contained those parts which had survived and which conveyed the sprit of the original. When Nr. 3 had been scrapped, usable parts had been salvaged. The cylinder and associated parts had been used in the factory as a stationary engine and these formed the heart of the reassembled vehicle.

Although the reassembled vehicle has come to be known as "Benz Patent-Motorwagen Nr. 1" and it shares some of that vehicle's more obvious characteristics (e.g. wire wheels), its structure and engine are much closer to Nr. 3 than to the vehicle depicted in the patent drawings. At the front, a new structure was created with a plan copying that in the patent drawings, but with a platform which was closer to the ground and with steering from Model 2.

The cylinder and cylinder head bear signs which link them to the patent drawings. Elsewhere in the engine, development was extensive between Nr. 1 and Nr. 3. The cylinder and flywheel were moved forward, the cylinder extension was changed, along with the carburettor (probably more than once); the fuel tank was moved under the seat; in the transmission, the belt was doubled in width. Most of these features were copied.

In sum, the cylinder and cylinder head are probably from 1885. Some parts of the engine may be from 1886-87. Other parts are a mixture of copies of the original, parts from later Patent-Motorwagen and reinterpretations in the spirit of the original.

Replicas of the reassembled vehicle have been produced from the mid-twentieth century. About 150 examples from various suppliers have been made. In 2001, Daimler (now Mercedes-Benz Group) began manufacturing replicas by hand. These can run on petrol but are not permitted on public roads..

Conclusion

The Patent-Motorwagen has been recognised as the first practical automobile (Nr. 2) and the first to enter production (Model 2). As its creator, Carl Benz has been hailed as the father and inventor of the automobile.

Sources

The development of the Benz Patent-Motorwagen is complicated and sources are often contradictory.

There appears to be only one surviving vehicle in near-original condition: a Model 2 in the Science Museum in London. There is a Model 3 in the Technical Museum in Vienna, but it was rebuilt in 1898 to have four wheels. As noted above, the vehicle in the Deutsches Museum in Munich was reassembled c.1895 using parts from the original vehicle. It gives something of the flavour of Nr. 1, Benz's vehicle of 1885, rather than showing what it looked like.

The principal sources used here (apart from the original vehicles) are:

• technical histories, especially two early ones: William Worby Beaumont's Motor Vehicles and Motors (1900) and Benz's Lebensfahrt (1925). The latter is both a memoir by Benz and a technical history written (in Benz's voice) mainly by his sons-in-law and a Professor Volk;
• early images, notably an engraving of Nr. 2, photographs of the original vehicle in 1887, a newspaper illustration of Carl and Bertha Benz driving a Model 2 in Munich in 1888 and contemporary photographs of a Model 2, a Model 3 and the reassembled prototype in the late 1890s;
• documents, notably patent 37435 and contemporary newspaper reports.

Although Worby Beaumont's detailed drawings and analysis of the Patent-Motorwagen are restricted to Nr. 1, for which the patent drawings exist, he also describes in detail the Benz "Ideal" of 1898-99. The family resemblance among Benz belt-drive cars makes it possible to identify where parts are likely to be, e.g. the fuel tank beneath the seat.

The identification of vehicles in images in the Mercedes-Benz Public Archive differs from those given here (all Patent-Motorwagen are identified as Model 3; they list Model 2 but do not identify any examples). A full analysis of images in the Public Archive which show original vehicles (including the reassembled vehicle in the Deutsches Museum but not replicas of it) is given at the end of this article.

Development and specifications

File:Patentmotorwagen.jpg

View of the reassembled original Patent-Motorwagen in Deutsches Museum, 1925

In 1873 Benz developed a successful gasoline-powered two-stroke piston engine. He was less successful in running a company and was forced to take on external shareholders, and to see his shareholding reduced to just 5%. His dream remained, to employ a gas engine and to create a horseless carriage.

Benz started work on his Motorwagen in 1884 in his own time, outside his responsibilities as a director of the company. He continually made changes to it, so it is hard to tie down details of its specification at any particular date. What can be said is that the first version which Benz was happy to take into Mannheim and be seen in was the Patent-Motorwagen Nr. 2 in summer 1886. This was his first practical car: it fixed the mistakes he had made in the design of Nr. 1 and was sufficiently reliable not to have to worry about constant breakdowns.

The Benz Patent-Motorwagen was a motor tricycle with a rear-mounted engine. The vehicle contained many new inventions. It had a frame of steel tubing with a floor of wooden slats. The steel-spoked wheels and solid rubber tyres in Nr. 1 were Benz's own design. They were replaced with wooden wheels in Nr. 2.

Steering and Suspension

File:Benz Nr 1 Plan (front).jpg

Plan of the front of Benz Patent-Motorwagen Nr. 1 showing the steering

Steering was by way of a pinion acting on a toothed rack that pivoted the front wheel. In Nr. 1 the stalk to control the steering was at the right edge and the rod to the front wheel ran above the floor. In Nr. 2 it was moved to the centre, above the counter-shaft. In the longer-wheelbase Nr. 3 and the production versions, it was moved further forward.

Elliptic springs were used at the back along with a beam axle and chain drive on both sides. The front wheel in Nr. 1 and Nr. 2 was unsprung; elliptic springs were added in Nr. 3 (1887) and used in all production models.

Transmission and Brakes

File:Benz Motorwagen 4-resized.JPG

View of the reassembled original vehicle showing the crossed drive belt; the patent drawings show it straight, 2015

A belt system served as a single-speed transmission, varying torque between a drive pulley and a two-part pulley on a counter-shaft. As the drive/brake lever was moved forward from its central position, the fork (J on the plan) shifted the belt from the loose pulley on the counter-shaft E to the fixed pulley F; this is similar to lifting the clutch pedal with a manual gearbox. As the drive/brake lever was moved back from its central position, the spindle L applied a steel band brake to the brake pulley, which was cast with the fixed pulley F (see the view of the underside of the reassembled vehicle, although it merges spindle L with rod G).

File:Benz Vis-a-vis Type Victoria (1893) jm64269.jpg

3 h.p. engine of a Benz Vis-à-vis (1893). The vertical flywheel is in the centre; to its right are two belt systems, one for each "gear"

After Nr. 1, control of the position of the belt was moved to a hand lever on a stalk in the centre of the vehicle. Brakes on the rear wheels were added to the band brake on the brake pulley and the lever on the left was dedicated to applying these.

Model 3 started as a single-speed vehicle with the flywheel horizontal. Later, a second, low gear was added. The transmission for this was provided by a second belt system to the right of the existing one (see the image of the Vis-à-vis of 1893), with separate hand levers to control whether that belt was driving the vehicle or not. The flywheel was changed from horizontal to vertical, eliminating the bevel gears between crankshaft and driveshaft. Worby Beaumont provides details of how the twin belt-drive system worked in the "Ideal" of 1898-99.

The selected belt drove the counter-shaft, which had a differential so that the wheels went at the correct speeds when cornering. Chains on each side provided the final drive from the counter-shaft to the rear wheels. There was no reverse.

Carburettor and Exhaust System

File:Benz Patent Carburettor.jpg

Benz Patent Carburettor (corrected)

In Nr. 1 the carburettor, with the fuel tank above, was in front of the cylinder. Its design was set out in patent 37345 and is shown here. The exhaust system is not described but in Model 2 the entire exhaust passed first through a silencer and then through the false base of the carburettor, to heat the fuel. The engraving of the 1886 vehicle shows the same arrangement.

The patent drawings show a squat fuel tank sitting on legs above a carburettor body comprising four parts, from top to bottom:

1. air / vaporised fuel output: safety valve at top centre; outlet to pipe to the intake valve on the right;
2. air / vaporised fuel separation: the lighter vaporised fuel rises more than the air; at the bottom right, some of the air / vaporised fuel mix is taken off in a pipe to the sight gauge 7 on the fuel line 6;
3. air intake and fuel vaporisation: this part contains three concentric units:
   • outer upper: air is admitted to the annulus around the inner fuel-containing vessel and is drawn down at increasing speed as the annulus narrows and the air passes through fuel before bubbling up through it;
   • outer lower: unknown;
   • inner: the vessel which contains the fuel;
4. heating by exhaust: exhaust is admitted at the left and passes around and below the inner fuel-containing vessel, heating it before exiting through holes in the base. At the centre is a valve through which fuel can be emptied from the entire system.

At the very bottom are legs on which the carburettor stood when Benz was working on it on a bench. There was no separate silencer: the entire exhaust passed through the base of the carburettor.

File:Benz Patent-Motorwagen Nr 2 Silencer Carburettor.jpg

Engine of Benz Patent-Motorwagen Nr. 2 showing Silencer and Carburettor

In Nr. 2 the carburettor (B in the engraving of Nr. 2) was moved to low down near the left edge. Between it and the engine cylinder was a vertical cylinder (A in the image). A pipe from the base of A leads to the side of B near its bottom. This matches the appearance of the Science Museum's Model 2. From its rusty appearance, cylinder A has evidently run hot and is the silencer. All its output is fed to a false base of the carburettor (this is indicated by the flange between the base and the main part of the cylinder) where it heated the fuel to help it vaporise. Fig.11 of Benz's Lebensfahrt is a schematic cross-section of Benz's later carburettors; it shows exhaust entering the false base on one side and leaving through fine holes in the bottom at the other.

In Nr. 2 the carburetted air rose in pipe C on its way to the intake valve. The knob D is in a similar position to the mixer valve in the reassembled original vehicle and its replicas.

From Nr. 3 onwards, the mixer valve was controlled by a pointer which was moved across a sector at the bottom left of the seat box. As can be seen on the Science Museum's Model 2, there was a horizontal rod which controlled the valve itself adjacent to the carburettor. The richness of the fuel/air mixture continued to be controlled in this way until a throttle knob was added c.1895.

Benz changed the carburettor often: Worby Beaumont describes the one in the British patent of 1886. That in Nr. 2 and Model 2 appears to be intermediate between this and the schematic in Fig.11 of Benz's Lebensfahrt.

On the evidence of the Science Museum's Model 2, carburettors were steel in the 1880s (it is better able to handle thermal stress from the exhaust). Copper and brass became fashionable in the 1890s, as in the engine of the 1893 Benz Vis-à-vis. The reassembled vehicle's fuel tank, carburettor, hub caps and drip-oilers bear witness to this.

Coolant system

File:Benz Nr 1 Coolant System.jpg

Coolant system of Benz Patent-Motorwagen Nr. 1

The patent drawings show a form of radiator above the cylinder with flow into it from what is now the drip-oil lubrication port at the top rear of the cylinder. The return flow is shown into the underside of the cylinder, near the cylinder head.

The radiator shown would have held a small volume of water and it had a hole (a on the left half of the diagram) at the top for steam to escape. Early radiators, including all Benz radiators before 1900 used "evaporative cooling": this meant that cooling was primarily by the extraction of the latent heat of vaporisation of water as it boils. In his 1894 journey in a Benz Viktoria (3 hp engine) , Theodor von Liebieg recorded water consumption up to 150 litres / 100 km = 2 mpg (fuel consumption was a more modest 21 litres / 100 km = 14 mpg). Boiling of the coolant water would have limited the distance Nr. 1 could travel before more water needed to be added.

The photo of the rear of Nr. 3 shows a small coolant tank above the cylinder with a neck. Its volume was greater than that of Nr. 1's radiator. Through successive iterations of Patent-Motorwagen, the volume of coolant water increased. Model 2's coolant water tank was much larger than Nr. 2's: see the photograph taken straight-on of the left side of the Science Museum's example. In Model 3, Benz added two substantial copper water tanks/radiators, one at each side of the engine. These are connected to the vessel above the cylinder. After 1895 a condenser (designed and patented by Émile Roger) was added, to try to reduce water consumption (a schematic cross-section is at Fig.13 of Benz's Lebensfahrt). Despite this, Worby Beamont comments:

On starting the motor, the tanks [labeled] W will be nearly full. . . After the motor has been working for a short time, the water in the jackets and the vessel [immediately above the cylinder] will begin to boil. . . This action will continue until a considerable part of the water is boiled away, when the tanks W must be refilled.

Wilhelm Maybach essentially solved this problem with his patents from 1897 onwards.

The patent drawings for Nr. 1 show two ports to the water jacket for the coolant system: on the top at the end remote from the cylinder head; and on the bottom next to the cylinder head. A new hole on the top of the cylinder would have been required when the first coolant water tank replaced the radiator in the patent drawings. There are signs that it wasn't part of the casting; the redundant hole on the top may have been converted to a drip-oiling point at this time.

Bore and Stroke

The original cylinder followed the practice of Benz's two-stroke stationary engines in using both a piston rod and a connecting rod, with a gudgeon pin between them. The connecting rod ran in the cylinder extension, which held the bearings for the crankshaft at its further end. This arrangement was maintained through to Nr. 3. Production models continued to use a cylinder extension but the cylinder and its extension were more squat and the piston rod was omitted.

The report in the Neue Badische Landeszeitung of 4 June 1886 states that the bore of the engine was 9 cm and that it developed about 1 h.p. at 300 rpm. The single cylinder of the reassembled vehicle has a bore of 9 cm and a stroke of 15 cm, giving a displacement of 954 cc (58.2 cu in). While the appearance of the cylinder extension of the reassembled vehicle matches that in the photograph of Nr.3, it differs from what is shown on the patent drawings. These show the outer diameter of the cylinder extension to have matched that of the cylinder (it was common for the cylinder extension also to have a water jacket).

File:BenzPatent37345Crankcase.png

Excerpt from Benz Patent 37345 for Motorwagen, showing cylinder extension

The "cut-out" for the motion of the connecting rod on the patent drawing is smaller than that in the reassembled original vehicle (and its replicas). The only reasons to increase the "cut-out" are for larger cranks or to increase the stroke . At 1.67, the stroke / bore ratio is high: surviving examples of Models 2 and 3 have ratios between 1 and 1.39. Model 2 was the next cylinder Benz made; it was square, with bore and stroke of 11cm. He is unlikely to have used a square cylinder in Model 2 unless he preferred it. The implication is that Benz's original cylinder (in Nr, 1) was also square, with bore and stroke of 9cm. Given the greater weight of Nr. 2, it is likely that the stroke was increased from Nr. 1 to Nr. 2.

File:Benz Patent Motorwagen 2.jpg

Engine of a replica of the reassembled original vehicle showing the cylinder and its extension

Assessment

The engine of the reassembled vehicle is a four-stroke engine with trembler coil ignition. When tested, it produced 0.68 PS (500 W; ²⁄₃ hp) at 250 rpm, although later tests by the University of Mannheim showed it to be capable of 0.91 PS (670 W; 0.9 hp) at 400 rpm. These details are shown in the Infobox. Technical details of the Model 2 and Model 3 are shown immediately before the section Patent-Motorwagen Model 2.

It was an extremely light engine for the period, weighing about 100 kg (220 lb). Although its cylinder extension and drip oiling system are alien to a modern mechanic, its use of a pushrod-operated poppet valve for exhaust is quite familiar. A large flywheel (horizontal until changed to vertical for the twin-belt Model 3) stabilized the single-cylinder engine's power output.

Patent-Motorwagen Nr. 1

File:BenzPatent37345.png

Figures 1-5 from Patent 37435 for Benz's Motorwagen, 1886

Motorwagen Nr. 1 is identified with the year 1885. During that year, Benz demonstrated it to the public for the first time, in the factory grounds. The vehicle was difficult to control and it collided with a wall.

Later, he took it out onto the public road, but suffered frequent mishaps:

. . . suddenly disaster strikes – in the form of the first "breakdown." The carriage slows down, and ... comes to a complete stop. The driver gets out, kneels down, tinkers, and patches it up. People gather, smiling and laughing. . . Wherever a treacherous fault was lurking, I didn't rest until it was discovered and eradicated. More and more often, the return journey was also made in motorised fashion, that is, without the assistance of people pushing or horses and cows pulling. At the same time, the driving distance had increased from 100 meters to a kilometre or more.

By the end of that year, Benz and his wife had become sufficiently confident that the vehicle would be of practical utility to prepare a patent application. This was submitted on 29 January 1886.

The patent is the best available evidence of the state of the Motorwagen at the end of 1885. The drawings show a motorised tricycle with wire wheels and a single-cylinder horizontal engine mounted fore-and-aft with cranks driving a horizontal flywheel, almost half of which projects behind the back of the rear wheels.

Apart from the piston cylinder, cylinder extension, cranks and the flywheel, the only equipment which the patent drawings show in the engine is a vertical cylinder in front of, and with a pipe to, the combustion chamber. This lay beneath the seat with its top at the level of the vehicle's floor. The patent drawings provide a section, which was reproduced in Benz's Lebensfahrt: as Fig. 9. It contains the evaporative carburettor, which typically would have held 1 litre of fuel, with a 3-litre fuel tank over it.

The patent drawings provide a cross-section of the vertical cylinder. This shows the fuel tank sitting above the carburettor, through the base of which the exhaust passes, heating the fuel and helping it to vaporise. There was a slide mixer valve on the pipe from the carburettor to the cylinder to adjust the richness of the air/fuel mixture. As the slide was moved in or out (probably by a lever), the air intake holes were covered or uncovered. No other exhaust processing is shown.

The patent drawings do not show an electrical system, but it is discussed in Benz's Lebensfahrt and illustrated in Fig 8. The patent drawings show what looks like the end of a (presumably wooden) box beneath the seat. Given its proximity to the cylinder head, it may have contained the battery and the coil for the ignition.

Drive was taken from the axis of the flywheel through bevel gears on the left side to a pulley, from which a belt ran straight (not crossed) to a pulley on the counter-shaft just in front of the rear wheels. This pulley is in two parts: one fixed to the counter-shaft; the other loose. By means of a lever (9 on Fig. 1 of the patent drawings) at the left of the vehicle, the rod 10 could be shifted to left or right, moving guide pins to transfer the belt from the loose pulley to the pulley fixed to the counter-shaft. Its effect was similar to that of putting an automatic car into Drive. The lever 9 could also be moved back, which applied a band brake to a brake pulley cast with the fixed pulley (see the image of the underside of the reassembled original vehicle).

The split pulley contained the differential, which ensured that the rotation of the counter-shafts on each side adjusted correctly when turning corners. Final drive was taken by roller chains between sprockets on the partial counter-shafts to sprockets connected to the wheels, which rotated freely on the rear axle.

Steering was controlled by a hand lever at the top of a stalk which was at the right edge of the vehicle, above the counter-shaft. At its bottom was a pinion which acted on a rack at the end of a rod, which ran diagonally immediately above the floor of the vehicle to a lever connected to the front wheel.

The engine was started by vigorously turning the flywheel. There was a step on the left side to ease getting into the vehicle: the floor was 800mm off the ground.

The controls – steering and drive/brake – both by hand, were at opposite edges of the vehicle, 1m apart. Benz must have set the flywheel turning at the back to get the engine started, then got into the vehicle on the left, sat down, adjusted the lever for the fuel/air mixture, moved the drive/brake lever forward to engage drive and then moved over to the right to drive it. To stop, he would have reversed this, moving the drive/brake lever all the way back to engage engine braking, waited for the vehicle to stop and then dismounted.

The seat consisted of a sprung squab for two people on large scroll springs which projected far in front of and behind the seat, hindering access to it. The arm rest and seat back appear to have been of wrought-iron.

Patent-Motorwagen Nr. 2

File:Benz Patent-Motorwagen Nr 2.jpg

The first practical motor car: Carl Benz's Patent-Motorwagen Nr. 2 of 1886

In early 1886, Benz became more confident about exposing his vehicle to the public. In his Lebensfahrt he writes.

Until then, I had preferred to conduct my test drives far from the city – on the factory grounds or out on the old, lonely ring road that still encircled the city of Mannheim and was hardly ever used – but from the spring of 1886 onward, I no longer shied away from people and their criticism. Now, twilight and darkness were no longer my favorite times for practising and rehearsing. Now I also appeared with my vehicle on the city's streets and squares, even the busiest ones.

A report appeared in the Neue Badische Landeszeitung of 4 June 1886:

For cycling enthusiasts, it should be of great interest to learn that a major advance in this field has been made by a new invention from the local firm Benz & Co. . . .This velocipede is powered by an engine similar in design to gas engines. The engine, with a cylinder bore of 9 cm and placed between the two rear wheels on springs above the wheel axle, represents, despite its small size, approximately one horsepower and makes 300 revolutions per minute, thereby increasing the vehicle's speed to that of an ordinary passenger train. Above the engine, which is powered by a type of gas, ligroin, contained in a reservoir and sufficient for an extended period, is the seat for two people, also mounted on double springs. In front of it are the steering and brake levers. By means of another lever, the vehicle is set in motion or stopped at will, by directing the belt, which transmits the motive power of the engine to the wheels, onto the loose or fixed pulley.

When William Worby Beaumont was preparing his book Motor Vehicles and Motors (1900), he corresponded with Benz. The image above is captioned "Benz Second Motor Tricycle Carriage made in 1886" and is

from an engraving lent me by Mr. Benz, of the second type of car he made. It differs from the first mainly in the seat or body.

The photographs of Nr. 3 show that the drive pulley and the belt match those of the reassembled vehicle rather than the patent drawings, on which they were about half this width. This suggests that the increase in the width of the belt, and therefore of the pulleys, occurred as part of the changes from Nr. 1 to Nr. 2. The bevel gears to the drive pulley were switched to the right between Nr. 1 and Nr. 2 and the crankshaft:driveshaft ratio changed from 2:1 to 1:1. As the reassembled original vehicle uses a crossed belt (as do all Benz vehicles), it seems likely that the change from straight to crossed belt was also at this time.

When the engine was moved forwards, the carburettor and fuel tank had to be moved. The similarity of the engine seen in the engraving of Nr. 2 to the Science Museum's Model 2 makes it possible to identify the silencer and carburettor as the two vertical cylinders to the left of the rear sprocket. The photograph of the rear of Nr. 3 shows a small-diameter pipe with a cock on it leading from the box under the seat. his indicates that the fuel tank was beneath the seat, the position used in Benz belt-drive vehicles from then on.

As well as the changes to shorten the overhang of the flywheel, the following changes were made:

• the floor at the front was lowered, curving up to the pivot for the front wheel;
• the steering control was moved from the right edge to the centre, enabling the driver to control the vehicle from a single position;
• the drive/brake lever at the left became the brake lever, with brakes on the wheels added to the band brake on a pulley fixed to the counter-shaft;
• the control to engage drive (by moving the belt from the loose to the fixed pulley) was moved to a hand lever on a separate stalk next to that for steering;
• the wheels were changed from wire towood with iron tyres;
• mudguards were added, both above the rear wheels and, beneath the floor, above the front wheel;
• lights (important for testing at night) were added;
• the seat was made more comfortable, with side and lumbar support, padded armrests and a padded seat-back;
• the scroll springs of the seat were reworked so that they lay beneath the seat and no longer inhibited access to the seat.

The carburettor seems to have been the part which gave Benz most trouble: he continued to develop it for many years with two further patents, the earlier being submitted in April 1887. Fig. 11 of his Lebensfahrt shows the definitive version with the air intake as a knob at the centre; on the Vis-à-vis of 1893 (and the reassembled original vehicle), the air intake knob is at one side. The Science Museum's Model 2 has a steel carburettor; brass appears to have been used later.

Patent-Motorwagen Nr. 3

Side view of Benz Patent-Motorwagen Nr. 3, 1887

This is the final form of the original vehicle before it was disassembled around the end of 1887. It is known from two photographs: that of the side, which is shown; and one of the rear.

The front looks much like the series production of Model 2 and has fully-elliptic springs as suspension from the front sub-frame. This is connected to the rear sub-frame, which is based on the main tubes on either side of the tubular steel frame of Nr. 2.

One change from Nr. 2 is to the brake lever. This now has a small transverse arm at the top which can be rotated. It probably locks the brakes in position and would be used when the brakes had been applied, to stop the vehicle moving when the vehicle had been stopped but the engine was still running.

At the rear, the scroll springs which supported the seat have been replaced by a wooden box. Their function as suspension has been replaced by the front elliptic springs. The sides of the wooden box do not reach the main tubes of the frame, but it is supported at front and back by members running between the main tubes.

On 8 April 1887 Benz applied for a patent for a 2-speed gearbox using epicyclic gears. Model 2, however, had only one gear and when a second belt was added to Model 3, it was by the addition of an extra belt system, not epicyclic gears.

Technical data

	Benz Patent-Motorwagen Models 2 and 3
Motor	Single-cylinder, four-stroke engine with a large horizontal (Model 2) or vertical (Model 3) flywheel, mounted at the rear.
Displacement	1045 cm³	1660 cm³	1990 cm³
Bore × Stroke	110 × 110 mm	115 × 160 mm	130 × 150 mm
Power	1103 W (1,5 PS) at 500 rpm	1839 W (2,5 PS) at 500 rpm	2206 W (3 PS) at 500 rpm
Fuel mixture preparation	Benz evaporative carburettor
Valve control	1 inlet mixer valve adjusted from a sector control at front bottom left of the seat 1 vertical exhaust valve controlled by eccentric rod, cam disc, rocker arm, and pushrod
Transmission	Belt drive to counter-shaft with loose and fixed pulleys, then chain drive to rear wheels Model 2: single speed with hand lever to shift belt between loose and fixed pulleys Model 3: two speeds, each with its own belt system and hand lever to shift that belt between loose and fixed pulleys
Front suspension	1 front steering fork, small transverse full-elliptic spring
Rear suspension	Rigid axle, full-elliptic spring
Steering	Rack and pinion; steering lever on a vertical stalk in the centre of the car
Rear track width	1190 mm
Wheelbase	1575 mm
Kerb weight	360 kg
Top speed	20 km/h
Price	3.000 ℳ (Model 2)

Patent-Motorwagen Model 2

The first production car: Benz Patent-Motorwagen Model 2, 1888

The year 1887 marked the transition for Benz & Cie. from development to production. The model which was sold was known as Model 2. It had a 1.5 PS (1.1 kW; 1.5 hp) engine; one speed; wooden external brakes on the rear wheels controlled by the lever to the left of the driver; and (on the evidence of the Science Museum's example) hybrid wooden/iron wheels. The engine with the flywheel was enclosed in a wooden box with a tonneau cover, through which the top of the coolant water tank projected. Optional extras were a folding half-hood and lights.

During the year, Émile Roger, a bicycle manufacturer in Paris who made Benz stationary engines under license, visited Carl Benz in Mannheim and bought a vehicle. Roger became Benz's agent for the Motorwagen and by the time Benz visited him in Paris in March 1888, Roger had sold one to Émile Levassor.

As well as the vehicles sold to Roger in 1887 and through Roger to Levassor in early 1888, there is photographic / pictorial evidence of:

• the vehicle which Benz himself used during 1888, which Bertha took for her trip to Pforzheim in August 1888 and in which Carl and Bertha were depicted driving around Munich in September 1888. This is often referred to as Nr. 3, but was actually a Model 2: the box beneath the seat extended back to cover the whole engine;
• the vehicle which appears as Fig. 27 of Benz's Lebensfahrt with the caption which starts "My first Series Production Car from 1888" (the side of its rear box is painted all over whereas the central panel of Benz's was varnished, as in the example in the Science Museum in London);
• the unique surviving example of Model 2 in the Science Museum in London.
• the vehicle in the street scene from 1890 in Mercedes-Benz Public Archive number C42836 (if this was a genuine scene);

Apart from finishes, all of these vehicles look the same and are clearly based on Nr. 3. We may infer that the vehicle Roger bought was also a Model 2. It follows that it was in 1887 that Benz's Patent-Motorwagen Model 2 started series production.

1888 Benz Patent-Motorwagen Model 2 on loan from Science Museum, London to Automuseum Dr Carl Benz, Ladenburg, 2014

The example in the Science Museum in London has a manufacturer's label stating that it was produced by Roger in Paris. It is known that Roger produced Benz vehicles from kits supplied by the factory in Mannheim and that at the Paris Expo he exhibited in the pavilion showing French products. Parts carried lower import taxes than vehicles and enabled Roger to sell the assembled vehicles and exhibit them as made in France. As the series production of Model 2 may not have been more than 5 or 6, it is hard to believe that this vehicle was not assembled and tested in Mannheim before being disassembled sufficiently to qualify as the export of parts.

The survival of the example in near-original condition makes it possible to study details of the construction. The wheels have alternate inner and outer spokes, as in a bicycle wheel. As was common in large wheels, the felloes are made from two laminas of steam-bent wood rather than from wood which was cut and shaped before being joined together. There is a thin iron hoop inside the iron tyre, to which the felloes were bolted as part of its construction. This was permanent and strengthened the wheel while retaining the ease with which the tyre could be replaced.

About 200mm from the axle, the inner spokes are enlarged and bolted to the rear sprocket of the chain drive. This addresses a problem which bedevilled early steam road vehicles: transmitting the torque to the rim of a wooden wheel (wood being required for its flexibility and better ride) without suffering breakages at the nave. The De Dion Bouton steam carriage which completed the 1894 Paris–Rouen race fastest used metal carriers to transmit torque to the heavy felloes. Goldsworthy Gurney had introduced them in his steam drag of 1829.

The front wheel has both the iron tyre (as with the rear wheel) and a solid rubber tyre over it. The rubber tyre provided grip on slippery road surfaces, necessary as it was the sole contact with the road to steer the vehicle.

The top of the coolant water tank projects through the cover over the engine. As cooling of the engine depended on the radiation of heat from this tank, it had to be exposed to ambient air.

Model 2 was superseded by the single-speed version of Model 3, probably in early 1889. It was in series production for little more than a year. It seems unlikely that production reached two digits.

Bertha Benz's trip to Pforzheim and the exhibition in Munich

Carl's wife Bertha came from a successful business family. Her dowry had enabled Benz to start his business. Her family had put more money into Benz & Cie when it had been in difficulties. She counseled Carl in business matters.

In his Lebensfahrt, Benz sets out the gestation of this trip:

It was the summer of 1888. The schools had closed their gates . . . in the minds of my boys—Eugen was 15, Richard 13—the audacious idea arose to take a newfangled holiday trip and drive out into the world in the car. "But we'll never get Father's permission," Richard lamented, deeply saddened. "Then we'll ask Mother," replied Eugen, "she's more daring than Father and will probably go with us." And so the plot was hatched.

No doubt Bertha saw the advantages of the publicity such a trip would create. She decided that the trip would be to her mother's in Pforzheim, some 50 miles away (60 miles by the route they took there; 50 miles for the return journey).

Bronze plaque outside the pharmacy in Wiesloch where Bertha Benz refuelled the car during the trip. The vehicle depicted is the reassembled original vehicle, not the Model 2 which was used.

They set off at the crack of dawn one day in early August 1888. To continue in Benz's words:

Eugen was at the wheel, his mother beside him, and Richard in the small back[-facing] seat. Less than an hour later, they reached Heidelberg on the lovely, level road. Everything went well until Wiesloch, too. But then, as the roads became hilly, the trouble began. The transmission wasn't designed for such steep inclines. Eugen and his mother had to get out and push while Richard steered. Going downhill, his mother felt uneasy. What if the simple wooden brake with its leather covering suddenly failed? Fortunately, this didn't happen on the entire journey. However, new leather pads had to be bought from the village cobblers and nailed on again and again from time to time. The journey continued, but the leisurely drive was over. Since the chains were stretching and slipping off the gears; they stopped in front of a village blacksmith. The villagers arrive and admire the motor car as if it had just fallen from the sky. After the chains had been tightened, they continue on their way—until the next breakdown. The car stalls because the fuel line is blocked. Mother's hatpin is just the right surgical instrument to repair the damage. During another breakdown, when the ignition failed, the "first female long-distance driver" even sacrificed her garter as insulation.

Although Eugen was driving when they set off, and Richard drove when Bertha and Eugen were pushing the car up a hill, Benz describes Bertha as the "first female long-distance driver", so she probably did most of the driving. On the way, they had to stop in Wiesloch, where Bertha bought some Ligroin fuel from a pharmacy.

Bertha was evidently enough of a mechanic to work out why the car had broken down and improvise solutions; she probably did most of the driving. However, it was the boys who came up with the idea of the trip; the use of leather coverings for the wooden brake blocks was an established practice.

Not only did this trip succeed in gaining publicity, the feedback from it led Carl to use a larger engine in Model 3 and to add an extra, low gear. This latter change required a substantial redesign of the engine bay.

What is evident from the account, however, is how primitive and unreliable the Model 2 was in August 1888. The sales to Émile Roger and Émile Levassor were both to professional manufacturing engineers, who would be as interested in understanding the capabilities of the new technology as in using it as a means of transport. As with steam coaches in Britain in the 1830s, ordinary users would soon tire of breakdowns and revert to the more reliable horse. In Roger's case, it led to his becoming Benz's agent for the Motorwagen in France; in Levassor's it helped him to build his first vehicles using the Daimler licence.

Exhibition in Munich, September 1888

Carl and Bertha Benz driving around Munich in their Model 2 Patent-Motorwagen, September 1888

One month later, Benz exhibited his vehicle at an industrial exhibition in Munich. In his Lebensfahrt he describes it as a triumph and his vehicle received a Gold Medal. He and Bertha drove around Munich to demonstrate the vehicle and their drives were reported in the local Neue Nachrichten on 16 and 18 September 1888. It was reported in the Leipzig Neue Illustrirte Zeitung of 1 December 1888 with the illustration shown. The illustration was reproduced in the Scientific American of 5 January 1889.

But of sales, it produced none.

Patent-Motorwagen Model 3

Carl Benz driving a Benz Patent-Motorwagen Model 3. His passenger is Josef Brecht, later his commercial director

Carl and Bertha were driving a Model 2 around Munich in September 1888, so we may infer that Model 3 was not ready by then. The most important sales opportunity in the next year was the 1889 Paris Exposition, from May - October 1889, where Benz had a display which was separate from Roger's. There are reports that Benz was selling Model 3 there, but this tells us nothing if the distinction between Model 2 and Model 3 had been lost, as it has been in Mercedes-Benz's records.

Nonetheless, it seems likely that Benz would have ensured that Model 3 was ready for the Paris Expo, where Roger was selling the Model 2. At first, the only changes from Model 2 were a new body and two large water tanks / radiators to supplement the coolant water tank above the cylinder (which was shrunk and lost its ability to be refilled). The water tanks / radiators were responsible for the distinctive horizontal louvres on the sides of the rear box of Model 3.

The image here showing Benz and Josef Brecht driving a Model 3 in a Rhineland landscape is based on a photograph of them outside the works in Mannheim. The photograph shows more clearly that this vehicle had a horizontal flywheel and so a single belt-drive. The main changes to the bodywork were:

• at the front, the rear-facing seat was replaced by a vertical panel, immediately behind the elliptic springs;
• at the back, the single wooden box which enclosed the engine and the seat was changed to emphasise the passenger-carrying part with the rear box subservient

Eugen Zardetti in his Benz Patent-Motorwagen Model 3, 1893

An optional extra was a single rear-facing seat, as used by Eugen Zardetti's passenger on the 1893 photograph of him in his Model 3. It was cantilevered out from the front panel, hanging over the front suspension and the front wheel, as can be seen more clearly in the image in the Mercedes-Benz Public Archive).

Engine of Benz Velo, 1894. The flywheel is immediately to the left of the left pulley

Bertha's trip to Pforzheim in August 1888 had shown the need for an extra, low "gear". This was implemented by adding a second belt-system, which involved changing the flywheel from horizontal to vertical and merging the crankshaft with the driveshaft (see the view of the engine of a Benz Velo of 1894). As this was substantial re-engineering, it is unlikely to have been ready for the opening of the Expo. The operation of the brakes was transferred from the hand lever in the centre to the large lever at the left side. That lever had controlled the movement of a single belt to engage drive. Movement of what were now two belts was undertaken by two interconnected hand levers in the middle, next to the steering.

Zardetti's appears to be the only surviving Model 3. It has the vertical flywheel, as can be seen beneath the rear box in the side-view of it in the Technical Museum in Vienna. That his Model 3 had two belt-systems can be inferred from the controls in the centre: as well as the main steering control there are two small hand levers, one for each belt system.

Benz Vis-à-vis (1893). The rear end is essentially a larger version of the Patent-Motorwagen Model 3. The brake blocks have leather brake pads.

The wheels appear to be of standard wooden construction: in the photograph of Carl Benz and Josef Brecht in a Model 3., the felloes are made from two laminas of bent wood. Later vehicles, e.g. the Vis-à-vis of 1893 have a metal rim to which the spokes are fixed by specially-purpose connectors. As can be seen in the meticulously-restored Vis-à-vis, the wooden brake blocks had been superseded by brass ones with leather brake pads.

Reassembly of the original vehicle

Benz Patent Motorwagen Nr. 1 in Deutsches Museum

Around 1895, the Sales Manager at Benz had the parts of the original vehicle sought out with a view to their reassembly. It seems likely that the engine cylinder and associated parts were indeed recovered from the factory, where they had served in a stationary engine. Of those parts, only the cylinder and the cylinder head are likely to have been part of Nr. 1: the cylinder extension does not correspond to the patent drawings and the greater weight of Nr. 2 would have demanded a more powerful engine, achieved by increasing the stroke.

3-wheeled prototype from 1893 of the Benz Velo with the Benz daughters aboard. The youngest child, Ellen was born in 1900.

Replica in Toyota Automobile Museum of Benz Patent-Motorwagen Nr. 1, 2022

What was produced was not, however, a reproduction of Nr. 1. The original Nr. 1 had been an impractical vehicle with limited range. A reproduction of Nr. 2, the first practical car, would have worked adequately, but was close in its appearance to the Model 3, which remained on the road, and to the larger Vis-à-vis and Viktoria. Instead, a vehicle was created which, with its wire wheels and light construction, was visibly related to the Velo then being sold. It incorporated enough of the improved technology to work reliably, and helped legitimise light vehicles as real cars.

Some parts reflected the then-current fashion for copper and brass: the carburettor, fuel tank and minor accessories such as hub caps and drip-oil lubricators. The surviving Model 2 shows some use of copper and brass where they are traditionally used, e.g. small-diameter pipes, knobs. Its carburettor was steel (better able to withstand the thermal stress of having the entire exhaust passed through its base), while the top of its coolant water tank appears to have been a combination of a ferrous casting and brass.

Design decisions were taken:

• the wire wheels were copied from Nr. 1, along with the band brake as the only means of braking;
• the engine and flywheel were positioned as in Nr. 2 onwards rather than in Nr. 1: with the cylinder head beneath the seat and the flywheel barely projecting behind the rear wheels;
• the platform of the reassembled vehicle was one-third closer to the ground than the original 800mm. This led to the characteristic rising bent tube which connects the front of the platform to the pivot of the front wheel;
• the steering control was placed as in Nr. 3, Model 2 and Model 3: in the centre, at a comfortable distance for a seated driver. In Nr. 1 the steering control was at the right edge, just in front of the seat;
• the drive/brake lever was aligned with the middle of the seat, rather than ahead of it. This was better ergonomically but meant that the spindle which it controlled was moved back and its function merged with that of the rod which shifted the belt;
• the seat itself, the padding of its arms and the ironwork which supported it were copied from Nr. 2; the patent drawings show no padding on the seat, wrought-iron arms and seat-back, and scroll-spring supports extending far in front and behind the seat;
• the bevel gears which convert the motion from the crankshaft to the driveshaft were copied from Nr. 1, being on the left and using a 2:1 ratio from the crankshaft to the driveshaft; Nr. 2 and Nr.3 (the source of the disassembled parts) used a 1:1 ratio with the bevel gears on the right;
• the carburettor matches that used in the Benz cars of 1896-99 rather than that used in Nr. 1 (see the section Development and specifications) or in Model 2;
• as a consequence, a silencer needed to be created to handle and expel the bulk of the exhaust: until at least 1888, the entire exhaust of Benz Patent-Motorwagen was expelled from the base of the carburettor;
• a separate brass fuel tank was placed as a transverse cylinder entirely separate from the carbuettor: in Nr. 1 the fuel tank was a squat vertical cylinder sitting on top of the carburettor; in Nr. 2, Nr.3 and the production models it was under the seat.

These establish the reassembled original vehicle as quite distinct from Nr. 1, Nr. 3 or some combination of them. In appearance, its closest relative appears to be the 1893 prototype of the Benz Velo.

With the passage of time, the vehicle created in 1895 has come to be seen as a replica of Nr. 1. Its origins and purpose have been lost. Images of it outside the pharmacy in Wiesloch outnumber those of Bertha, Eugen and Richard in a Model 2.

Carl Benz on the reassembled original Patent-Motorwagen (with Bertha standing to his right), Munich, 12 July 1925

At some time between 1900 and 1923, further changes were made. In the photos from 1900, it is completely open beneath the seat and the top of the cylinder head can be seen. By the 1920s, photos show slats being carried up beneath the seat, hiding the engine. Through them projects a knob to control the fuel/air mixture. Less obvious is that, right at the top of the slats above this knob are two brass wing-nuts where the electrical system can be connected or disconnected (zoom into this image above the knob). Their use in a replica is explained in this video. Perhaps a desire for greater safety when demonstrating the vehicle led to this change. They are included in modern replicas.

On 12 July 1925 the Allgemeine Schnauferl-Club organised a parade of historic vehicles in Munich which Benz headed, driving his Patent-Motorwagen for one final time.

Changes to parts appear to have been made since 1925: the wooden boxes for the battery and coil are smaller and copper pipework, associated fittings and the base of the carburettor show signs that they have been replaced.

Mercedes-Benz Public Archive

At 18 May 2026 the Mercedes-Benz Public Archive's entries for "Model 3; 3 hp" included images of Nr. 2, Nr. 3 and Model 2 but not Model 3. The images may be identified as:

• 22389: Model 2 – this is a higher-resolution version of the out-of-copyright Fig. 27 of Benz's Lebensfahrt. Its caption there is Mein erster Serienwagen von 1888. 1,5 PS, 2 Geschwindigkeiten bis zirka 16 km/Std., damaliger Preis 3000 Mark (My first series-produced car of 1888. 1.5 h.p., 2 speeds to approx. 10 mph, original price 3000 Mark)
• 22390: Nr.3. – this is a higher-resolution version of the out-of-copyright image on Wikimedia Commons
• 22588: Nr. 2 – this was used as advertising in 1888; the report beneath from the Munich Neueste Nachrichten of 16 September 1888 references the exhibition in Munich and describes the vehicle as eine viersitzige Komfortable Kaleche mit umlegbarem Regenbach (a comfortable four-seat calèche with a fold-down rain-hood). The engraving of Nr. 2 was published on p.80 of Worby Beaumont (1900): Motor Vehicles and Motors. A high-resolution version of it cropped to show only the vehicle is on Wikimedia Commons and is used in this article.
• 31809: Model 2 – Carl and Bertha Benz driving round Munich in their Model 2 in September 1888. This image (an engraving, not a photograph) was published in the Leipzig Neue Illustrirte Zeitung of 1 December 1888 and was subsequently reproduced in the Scientific American. It is out of copyright and on Wikimedia Commons.
• 82441: Nr. 2 – another copy of 22588
• B39394: Model 2 – this is a painting of the trip by Bertha, Eugen and Richard from Mannheim to Pforzheim in early August 1888.
• C42836: Model 2 – engraving from unidentified source of a Model 2 in a street around 1890

The entries for "Model 3; 2.5 hp" included some of those listed above together with images of the Science Museum's Model 2 when it was on loan to Automuseum Dr Carl Benz in Ladenburg. Among them is:

• 2008DIG1669: photograph of the Science Museum's Model 2 to the left of a modern replica of the reassembled original vehicle.

The entries for "Model 3; 1.5 hp" include some of those listed for the Model 3; 3 h.p and in addition:

• 22584: Nr. 2 – this is similar to 22588 and is an advertisement from a catalogue; if the catalogue was published, the image would now be out of copyright. It offers the most detailed view of the engine of Nr. 2 and complements the photograph of the rear of Nr. 3. That it was based on a photograph is evident from the composite photograph and CAD rendering which appears as Archive number 46305.
• A33374: Model 3 – this shows Carl Benz driving a Model 3 with Josef Brecht beside him outside the Benz factory on Waldhofstrasse. It is evidently the basis of the engraving of Model 3 with the same occupants but in a Rhineland landscape with vineyards;
• 1988M51: Model 3 – 1892 advertisement for Model 3 quoting the price as 3000 Marks. This contains an engraving based on A33374 which was published on p.81 of Worby Beaumont (1900): Motor Vehicles and Motors. A high-resolution version of it cropped to show only the vehicle is on Wikimedia Commons and is used in this article.

The description correctly identified the following image as being of Model 3 but it is not tagged to be returned in a search for Model 3:

• 1989M8: Model 3 – Eugen Zardetti and his family in a two-speed Model 3 on 19 March 1893. This is a higher-resolution version of the out-of-copyright image on Wikimedia Commons

At 18 May 2026 there were no entries for Model 2, but in addition to the images listed above, there was:

• 2007DIG2638: advertisement from 1888 for Émile Roger which shows (leftmost image) a Model 2 with a straight panel at the front rather than the rear-facing front seat.

At 18 May 2026 the entries for Model 1 mostly related to replicas of the reassembled original vehicle. Those which related to the reassembled original vehicle itself were:

• 7689: this is a higher-resolution version of the out-of-copyright Fig 31 of Benz's Lebensfahrt
• 22680: this appears to be the result of attempting to enhance the out-of-copyright Fig 17 of Benz's Lebensafhrt
• H3365: photograph of the reassembled original vehicle being driven at the Baden-Baden Automobile Tournament, 10-15 July 1923.

See also

• History of the automobile
• Benz Velo (later four-wheel model)

External links

• Patent 37435, by Karl Benz for his 1885 Motorwagon The birth certificate of the automobile – the German patent application of January 29, 1886, that was granted on November 2, 1886, to Benz & Company in Mannheim
• Automuseum Dr. Carl Benz, Ladenburg (Heidelberg)
• John H. Lienhard on Bertha Benz's ride

Preceded by none

Fastest street-legal production car 19 km/h (11.81 mph)

Succeeded by Daimler Motorized Carriage