The unknown story of the Steinwinter Supercargo 2040, the visionary truck with an interior that fits under the trailer

If in the 60s truck designers had focused especially on gas turbine engines in imagining the future of trucks, then in the 70s they focused mostly on driver comfort, since that was the period when long truck routes were very popular, and the respect for the comfort that a driver had to have on board in such distances was commensurate. However, in the history of curious creations of visionary trucks there is one truck that was admired by everyone - from the authorities to the general public - except the truck drivers, that is, exactly those for whom it was created. It's called Steinwinter Supercargo 2040 and it incorporates some of the most interesting ideas in truck construction.

The truck was created by the Steinwinter team from Stuttgart, Germany, and especially by its founder, Manfred Steinwinter. His company specialized in the conversion and production of vehicles with small engines, which were classified in lighter permissive classes, but the creation for which Manfred went down in history is precisely this ambitious truck.

The idea behind it was as simple as it was revolutionary. Manfred Steinwinter had the vision to build a tractor head so flat that it would fit under the standard trailer used in truck transport. In his view, this formula would allow increased driving comfort, better maneuverability, cost reduction, but also a greater total load, since the entire tractor head was smaller and lighter.

Steinwinter patented his idea in 1979, a time when Mercedes, for example, was still building hooded trucks. After filing the patent papers, Steinwinter assembled a team (including Axel Breun, who later worked as a designer at Renault) to build the first real truck, to present and convince the world. This truck, called Supercargo 2040, was presented at the IAA show in Germany, in 1983 and fascinated the world.

The team of designers managed to design a tractor head, the height of which barely exceeded the height of normal 22.5 radius truck wheels. This tractor was only 3.83 ft (1.17 m) tall and 21.3 ft (6.5 m) long.

The whole part in front of the front deck was a luxurious cabin, rather reminiscent of a Lamborghini. The driving position was lowered as in a supercar, the seats were profiled, with strong lateral support and multiple adjustments, coming from Recaro, the steering wheel was just as in a car, as were the instrument panels. There is a central tunnel and console facing the driver, dotted with all kinds of buttons. By the way, the central tunnel and the console separated the driver's seat from two other adjacent seats, with the same profile.

Photo: The interior of the Steinwinter Supercargo 2040 truck

The problem is that behind the three seats there is no sleeping space for the driver, there is the engine compartment. It was assumed that the driver would lie down in the middle seat, benefiting from a flat surface and be able to open the back door, where there was also a wardrobe.

By the way, the engine was sourced from Mercedes, as were the frame and axles. The engine was codenamed OM 422 and developed 400 hp and 1,549 lb-ft (2,100 Nm) of torque, and the truck had a payload 20% higher than a normal truck with a regular tractor head. The tractor head had been developed in such a way that it could receive any other engine, from any other manufacturer, however. And by the way, the truck had air suspension, ABS, limited slip differential and air conditioning inside.

Only a 4x2 formula, with two axles, was taken into account, since if more axles were mounted, the length of the truck would have to increase, and it would not fit under the available space of the trailer. And so, in the demonstrations and in the images of this article, a Schmitz trailer was used, elongated to the maximum permissible at the time, but later the length in Europe was restricted, so that by today's standards this truck would have come out slightly to the front.

The authorities in Baden-Württemberg were so excited about the idea that they paid almost 1 million marks to promote this truck as a future solution, in addition to the 2 million spent by the company on its development. They also ensured rapid homologation, so that it could be driven on public roads, and soon the first tests began, when the truck arrived in the hands of journalists and truck drivers, and this is where the real problems began.

Visibility turned out to be exceptionally poor. The driver could not see the whole of his truck, especially in the upper rear. At intersections, he could not see the traffic lights mounted at normal height, if he stopped regularly, at the line, and he had no chance to see the ones at the top. In turns, it was difficult to notice the dimensions of the tractor head, and the corner of the trailer remained in the other direction. So, effectively, if you turned right, you had to look at the front right corner of the tractor head, where it was going, and you had to take into account the top left corner of the trailer, which was not much further back, but almost as protruding to the front. This required drivers to often use two traffic lanes for the simplest maneuvers. And on top of that, the truck had a great tendency to understeer.

Lacking the usual air vents, the engine had a tendency to overheat on climbs, which raised big questions about the long-term reliability of such a truck, or at the time, the minimum guaranteed life of a truck was regulated by law at 1 million km. And the aerodynamics of the flat shape of the trailer, which ended up being the one that cut through the air, were not exactly perfect.

And on top of everything, the driver no longer felt like the master of the road and the truck, but a pawn hidden under the trailer, made to do a job that he could not fully estimate and control. Practically all the tests in the magazines and all the truck drivers, who got to drive it, mentioned more shortcomings than advantages. And those from Steinwinter, having the funding of the authorities to demonstrate it, started to promote it to the Chinese as well, and even transported it to the USA, in order to convince the American drivers. One driver from the US made an accident with it, and that meant the end of the Supercargo 2040 demonstrations. The truck was brought back to Stuttgart and is said to have been repaired and sold to a collector. And its creator, Manfred Steinwinter, passed away in 2018.