AMC straight-6 engine

The AMC straight-6 is a family of inline six-cylinder engines built by American Motors Corporation and used in its passenger cars and in Jeep vehicles from 1964 until 2006, a run that carried on under Chrysler after it bought AMC in 1987. Its ancestry goes back to the small Rambler six that Nash Motors designed, which AMC redesigned with overhead valves for the 1956 model year and kept in production until 1965. In 1964 AMC introduced an entirely new short-stroke design with a seven-main-bearing crankshaft, first sold as the 232 cubic inch Torque Command six and later offered as the 199 and the 258, while AMC's Mexican subsidiary built its own 252 and 282 versions. The last member of the family was the 4.0 litre engine introduced for the 1987 Jeep Cherokee, now regarded as one of the best off-road engines ever fitted to a four-wheel-drive vehicle.