1876Reputable sourceWell documented
Otto's Four-Stroke Engine
On the timeline · around 1876 ·
What happened
In 1876 the German engineer Nicolaus Otto built the first practical and successful four-stroke internal-combustion engine, in which a piston draws in and compresses a fuel-and-air mixture, is driven down by its ignition, then expels the exhaust — the sequence still called the 'Otto cycle' in his honour. Reliable, efficient and comparatively quiet, more than 30,000 were built within a decade.
Why it matters
The four-stroke engine is the direct ancestor of the petrol engine that still powers most cars today. It gave the automobile pioneers who followed a compact, dependable source of power to put on wheels.