Benz Patent-Motorwagen

Carl Benz completes and privately tests his first Motorwagen

Before there was a patent or a public road demonstration, there was one troublesome three-wheeler undergoing secret trials in a Mannheim factory yard — and repeatedly ending up against the wall.

1885: a machine designed whole

During 1885 in Mannheim, Carl Benz completed a three-wheeled prototype that was designed from the outset as an integrated petrol-engined road vehicle — not an engine bolted into a carriage. Its horizontal single-cylinder four-stroke engine, tubular chassis, belt-and-chain transmission and rack steering for the single front wheel were meant to work as one system.

Sources differ on when in the year it was ready: one museum account says spring, a national museum places its successful emergence in autumn. Initial trials were conducted privately in the factory yard to preserve secrecy.

A 96-kilogram engine in a 263-kilogram vehicle

The complete vehicle weighed about 263 kilograms, of which roughly 96 kilograms was the engine alone. It produced about 0.75 PS at 300–400 rpm.

One design choice shows how little was settled: Benz worried that a vertical flywheel would upset the vehicle in corners, so he mounted the 27-kilogram flywheel horizontally.

Not yet public, not yet patented

Development continued after the vehicle repeatedly ran into the yard wall. By the end of the year Benz possessed an operating prototype, but it had not been patented, publicly demonstrated or offered commercially.

Even the familiar label is retrospective for this year. The name “Benz Patent-Motorwagen” presumes a patent, and the application was not filed until January 1886.

Sources

Researched 23 Aug 2026 6 sources 3 audit passes

How this was checked

Researched from the web into a fact sheet, rewritten from that sheet, then audited against it by a different model. How the pipeline works →

What the sources leave uncertain

The year 1885 is well supported, but sources differ on finer timing: one museum account says the prototype was ready in spring, while another national museum places its successful emergence in autumn. No exact completion day is secure.
The familiar name “Benz Patent-Motorwagen” is retrospective for the 1885 event because the patent application was not filed until January 1886.