Wilhelm Maybach was born on 9 February 1846 in Heilbronn, where he grew up as one of six children. By the age of ten he had been made an orphan. He attended school at the Reutlinger Bruderhaus, where Gustav Werner, the founder and director of the school, spotted and nurtured the boy's technical talents.

In 1865, Maybach also met Gottlieb Daimler in Reutlingen and they became congenial companions. Maybach remained a very close friend right up until Daimler's death in 1900. In September 1869, he worked in Karlsruhe with Daimler and later moved to the Deutz engine works. There he began work on designs for a light, high-speed combustion engine suitable for use in water, land-based and airborne vehicles.

Daimler left Deutz Gasmotorenfabrik in mid-1882 following differences with the Management Board. In October 1882, Wilhelm Maybach followed him to Cannstatt to implement his designs for a light, high-speed combustion engine. During extensive research work, Maybach unearthed a patent belonging to an Englishman named Watson. It described an unregulated hot-tube ignition system – an essential element in generating high engine speeds. In 1883, he developed the first horizontal engine, followed by the Grandfather Clock, an engine with a vertically fixed cylinder, which was particularly suited to installation in vehicles. In 1885, the new engine was installed first in a wooden "riding car" and subsequently, a year later, in a carriage. But Maybach was not content with merely producing engines for carriages.

Maybach subsequently developed the steel-wheel car. This vehicle saw the introduction of the gear drive to automotive engineering. Presented to the public for the first time at the 1889 Paris World Exhibition, Maybach's steel-wheel car also precipitated the birth of the French automotive industry.

When Gottlieb Daimler founded Daimler-Motoren-Gesellschaft (DMG) with Max Duttenhofer and Wilhelm Lorenz in November 1890, Maybach was appointed Chief Design Engineer. He left the company in February 1891, however, citing unacceptable terms of contract.

For the next 18 months, Maybach continues his design work at home. In the autumn of 1892, with the financial backing of Daimler, he begins development work in Hotel Hermann in Cannstatt. This yields such important designs as the spray-nozzle carburettor, the Phoenix engine and improvements to elements of the belt-drive system. At the request of English industrialist Frederick Simms, Maybach is reinstalled as Technical Director at DMG in November 1895. There he develops the tubular radiator with fan and later the honeycomb radiator. The "Roi des Constructeurs" (King of Designers), as the French call him, goes from one technical achievement to another, creating the first four-cylinder automobile engine and in 1898/99 a whole generation of engines comprising five models and producing between 6 hp (4 kW) and 23 hp (17 kW).