Enhancement packages and feature suites have successfully kept the vehicles in the M1 series in service with the U.S. military to this day. The M1A2 Abrams, which was introduced in 1986 and first sent to production in 1990, featured a redesigned commander’s station with 360-degree night vision and independent thermal sighting. It also replaced the diesel engine on the M1 and M1A1 variants with a more powerful gas turbine engine.