Car Features
Rear- and mid-engined Mercedes-Benz cars
Several European makers, including Mercedes-Benz, developed rear-engined cars in the 1930s, undoubtedly inspired by the work of Ferdinand Porsche and Tatra’s Hans Ledwinka, who also invented the backbone chassis.
It’s often not recognised that the very first automobiles, back in 1886, were rear-engined: the patent motor car of Carl Benz and the motor carriage of Gottlieb Daimler. However, as power went up, the need to position engine and radiator in the airstream saw most car makers adopt front-mounted engines.
The front-engined, rear-wheel-drive layout was fine for medium and large cars, but detracted a disproportionate amount of interior space from smaller cars. The successive financial crises of the early 1920s and 1930s, along with the Weimar Republic’s inflationary economy, dictated a need for smaller, cheaper cars in Germany. Having an up-front engine and transmission, prop shaft and driving rear axle stole interior space from a small car and that problem intrigued automotive engineers.
Some makers opted to solve the problem by integrating the power and transmission up front in a front-wheel-drive design, while in Germany the preferred route was a rear engine with rear-wheel-drive. A bonus was the need for independent suspension – at least at the ‘drive’ end – and that gave these small cars improved ride quality.
Mercedes-Benz rear-engined cars
Hans Nibel and Max Wagner were open-minded engineers at Benz & Cie in the early 1920s, and would later play leading roles at Daimler-Benz in Stuttgart-Untertürkheim, in restructuring the passenger car range.
At Benz in 1922, they embarked on the development of a state-of-the-art, mid-engined racing car, known as the Benz RH (Rennwagen Heckmotor, or rear-engined racing car).
On 9th September 1923, Benz achieved considerable success at the European Grand Prix in Monza, when two teardrop racers finished fourth and fifth, despite their lack of competitive power.
That experience proved invaluable when, shortly after the merger of Benz & Cie and Daimler-Motoren-Gesellschaft in 1926, the new company focussed on car development of the bottom end of the model range.
Several designs for smaller vehicles with displacements of 1.3 litres and 1.4 litres were created under chief engineer, Ferdinand Porsche, but these prototypes had front-mounted, side-valve engines and rigid-axle chassis. Then M-B designer Josef Müller later wrote of this period:
“The days when we could sell only large and prestigious vehicles seemed to be gone for good and we were on the brink of a new type of popular motoring.
“The four passengers deserved to be given the best suspension possible between the axles.”
Between late 1931 and 1934 the design department came up with numerous designs for small, four-seat, rear-engined cars with air-cooled boxer engines and liquid-cooled three- and four-cylinder engines – some of which were transverse-mounted above the rear axle, like some Tatras. At the same time, vehicles were also drawn with front-mounted engines and front-wheel drive.
VW Archive
After 1933, in Germany, there was also another looming project – the People’s Car – mandated by Adolf Hitler. This term was used at the time to denote a category and desired orientation rather than a specific model. Volkswagenwerk GmbH didn’t start series production of the vehicle that would later become famous as the ‘Beetle’ until 1939.
Daimler-Benz had no intention of leaving the small-car market wholly to VW. Unveiled in 1931, the Mercedes-Benz 170 (W15) featured independently-suspended front and rear swing axles, but had a front engine and rear-wheel drive.
The same year saw the launch of the 1.2‑litre W17 Mercedes-Benz rear-engined prototype. Its air-cooled, horizontally-opposed, four-cylinder, overhead-valve engine developed 25bhp. (The W17 concept anticipated a number of key features that later appeared in the Volkswagen ‘Beetle’.)
Although it had a rear swing-axle, the W17 had a rigid front axle with semi-elliptic springs. Soon after, the designers in Untertürkheim came up with a rear-engined alternative and this one made it to the production line.
The Mercedes-Benz 130 was unveiled in March 1934 at the International Motor and Motorcycle Show in Berlin, together with the much more spectacular 500K Autobahn-Kurierwagen.
At the time of its launch, the 130 (W23), was Daimler-Benz’s smallest series-produced passenger car and the company’s first rear-engined model, joining Tatra’s 77, in being the first mass-produced rear-engined cars in history.
The 130, designed by Hans Nibel and Max Wagner, featured a Tatra-style tubular backbone chassis that was forked at the rear, to accommodate engine and transmission.
The 130’s 1.3-litre, side-valve, water-cooled engine had a power output of 26bhp. The front wheels were independently-suspended by upper and lower transverse leaf springs. At the rear, the 130 had swing-axles, with a single coil spring on each side.
At the time of its launch, the 130 was available as a bare chassis, two-door saloon, two-door convertible saloon and two-door tourer.
In 1934/35, 130 Kübelwagen variations were manufactured, but the Wehrmacht opted for the air-cooled VW version. So, a civil variant called the 130 Reichsautobahn was built as an open, two-door tourer, with externally-mounted folding spade and other accessories.
The 130 soon earned an unenviable reputation, thanks to ‘dodgy’ handling that was a result of 35-65-percent front-rear weight bias, combined with the notorious camber changes of swing-axle rear suspension.
(Both Mercedes-Benz and VW had a lasting love affair with swing-axle suspension that lasted until the 1970s, despite obvious handling issues.)
In 1935, the 130 was relaunched in revised form, with changes to the tuning of springs and shock absorbers, modified front wheel camber and less-direct steering.
At the same time, the interior was upgraded with carpet, in place of rubber mats, superior upholstery, adjustable front seats, footwell ventilation flaps and two-tone paintwork.
However, this facelift and further 1935 improvements failed to deliver the hoped-for boost in sales, so the need for a successor was obvious. A total of only 4298 vehicles had been produced between November 1933 and April 1936.
In February 1936, the 130 was replaced by the more powerful and redesigned 170H, but the 130 continued to feature in the price list as a discontinued model until February 1937.
Mid-engined derivatives
In parallel with development of the 170H was the sporting, two-seater Mercedes-Benz 150 with coupé body that gave more than just a nod to the 1920s RH racing car.
The 150 competition car had its engine and transmission rotated through 180 degrees, making it a mid-engined car – a design that would many years later become the standard for all global track-competition vehicles.
Based on the 1.3‑litre unit from the 130, the 150 engine delivered 55bhp – around double the original output. Displacement was raised to the 1.5-litre racing class limit and the new head had valves operated by a spur-gear-driven overhead camshaft. The original updraft carburettor gave way to dual side-draft carburettors.
The 150 sports saloon won four gold medals at the 2000-kilometre endurance race across Germany, in July 1934. One of the vehicles was driven by a young driver, who had started out in 1933 as a racing mechanic and was destined from 1935 onwards to be behind the steering wheels of the legendary Silver Arrows: Hermann Lang.
The sports saloon’s greatest triumph was in the Liège-Rome-Liège Rally, in August 1934, driven by Hans-Joachim Bernet. He led the field between Rome and Pisa, and on reaching the finishing line without penalty points, won the best-placed, closed-body car prize.
Only six Mercedes-Benz 150 sports saloons were sold in 1934, but an open-top variant of the competition car, the Mercedes-Benz 150 Sport Roadster, made its debut at the IAMA in Berlin, in February 1935. It became part of the official sales range and was offered until 1936, but as few as five cars were built.
The Mercedes-Benz Museum has one of those sports roadsters on display.
The last rear-engined ‘Benz
The 170H (W28), which superseded the 130, made its debut, in February 1936, at the International Motor and Motorcycle Show in Berlin, together with its front-engined sibling, the 170V.
The 170H and 170V shared a 1.6‑litre engine that was the 130’s bored and stroked 1.3-litre. Power was unchanged, but torque was improved, allowing for the addition of an overdrive top gear in the four-speed box. A cabin heater was standard.
An interesting addition was compressed-air radiator cooling, thanks to a blower wheel driven by the alternator shaft that forced air through the radiator.
The backbone chassis was carried over, but double-acting shock absorbers were fitted. Although chassis tuning yielded a significant improvement over the 130, handling still took some getting used to.
Like its predecessor, the two-door 170H was available in saloon and convertible-saloon versions.
Between July 1935 and October 1939, only 1507 170H cars were built, while the lower-priced, more conservative and easier-to-drive 170 V did much better.
A 170H was used to conduct experiments with low-drag bodywork, designed by engineer Karl Schlör and built by coach builders, Ludewig. This experimental car posted an average maximum speed of 146km/h under the auspices of the Göttingen Aerodynamics Research Institute.
Smart Fortwo – Vauxford
Post WWII, Daimler-Benz showed no enthusiasm for rear-engined, rear-wheel-drive or front-wheel-drive designs. In fact, the concept of modular engine-transmission-final-drive designs was abandoned by the company until 1997-1998, when the Mercedes-Benz A Class front-wheel-drive and ‘Benz-owned Smart Fortwo rear-wheel-drive appeared.
We’re indebted to the Mercedes-Benz Archive for information and photos.
ADVERTISEMENTS
