The Cummins L10 was an inline, six-cylinder, 10-litre diesel engine. Development began in the mid-1970s, and prototypes were built and tested in 1978. Development continued to the L10's commercial launch in 1982. The engine became a popular choice for transit buses. The L10 was discontinued in January 1994 and replaced by the Cummins M11 for transit applications.
The compressed natural gas version of the L10 was called the L10G.