The Harley-Davidson Softail family is named for its hidden horizontal rear shock absorbers. The Heritage Softail Classic was released in 1986, followed by the Springer Softail in 1988. The first softail transmitted power from a 1,340-cubic centimeter, V-twin, Evolution engine, which idled cooler and did not leak oil like its predecessor. The Softail Deuce, which appeared in 2000, upgraded the Softails to Twin-Cam, 88-B engines. Fuel injection was added in 2001.