This page chronicles the many automobile engines that General Motors has used in its various marques.
GM currently uses certain terminology to refer to groups of engines, but this terminology does not necessarily isolate families. In other words, not all of the Vortec engines share common ancestry.
GM also uses three-character RPO codes to refer to specific engine models. Many of these have been reused over the years, and new RPO codes are sometimes used for very similar engines, however.
Unlike Chrysler and Ford, each GM division had its own line of engines until the 1970s. For this reason, making sense of GM engines can be difficult. For example, Buick, Chevrolet, Oldsmobile, and Pontiac each had a different 350 in³ V8 design!
GM has produced a few families of straight-6 engines. The first was introduced 1929 to replace the straight-4 previously used in Chevrolet cars. It lasted until the 1970s in GM cars, and all the way until 1985 in Chevrolet and GMC trucks. A new straight-6 was introduced in 2002 as part of GM's Atlas truck engine program.
General Motors produced just one flat-6 engine, the 1960s Chevrolet Corvair engine. This air-cooled aluminum engine was notable for many things, including being one of the first turbocharged engines in history.
General Motors was the pioneer of the V6 engine in the United States, putting the first American V6, the Buick Special's 198 in³ V6, on the road in 1962. But the company quickly lost interest in the small engine family and sold it to Kaiser in 1967. In the midst of the fuel crisis of the 1970s, GM realized that a V6 engine would be an excellent alternative to bulky straight-6 and large V8 engines, so the company bought the design back and launched the familiar 3800 line.
At that same time, the company began designing a 60° V6 for their new compact cars. This line started slowly, powering only the smallest cars. One notable version was the DOHC LQ1, designed with Lotus. The smooth and compact 60° engine has become GM's platform of the future, spawning the new global High Value family.
Other V6es came and went in recent decades, including the V8-derived Olds Diesel 4.3 and Vortec 4300 and Premium V-based LX5. The European Opel/Cadillac/Saturn 54° V6 has spawned the company's other future V6, the global High Feature DOHC engine.
From the 1950s through the 1970s, each GM division had its own V8 engine family. Many were shared among other divisions, but each design is most-closely associated with its own division. Chevrolet had two different V8s, the big-block and small-block. Today, there are only three V8 engines produced by GM: Chevrolet's Generation IV small-block and big-block, and Cadillac's advanced DOHC V8, the Northstar.
GM later standardized on the later generations of the Chevrolet design:
Other GM V8 engines include the following:
Cadillac has produced just one V12 engine, in the 1930s. Since then, the company has twice prepared a new V12, but has not yet brought one into production.
Cadillac is a rarity in having produced two of only three production V16 engines in history:
