22. Ford 300 CID
Even though Ford gained fame for its V8s, ordinary customers and working men preferred its 300 CID straight-six offering that was introduced in 1965 and remained in production for 31 years. The 300 CID was the simple straight-six engine, which was designed to be a standard engine option on F-Series trucks and Ford Bronco.

Initially delivering 170 hp, this six-cylinder was praised for its durability, high torque figure, dependability, and affordability. Ford sold it as a crate engine, and it was also used for machines, trucks, and boats.