The Truck, Utility, l/4-Ton, 4×4, M151 (M151 ) was the successor to the Korean War M38 and M38A1jeepLight Utility Vehicles. Commonly referred to as a "jeep" or "quarter-ton", it was produced from 1959 through 1982 and served in the Vietnam War. The M151 had a monocoque design making it roomier than previous jeep designs, and incorporated an independent suspension with coil springs. It has since been replaced by the larger AM General HMMWV in most utility roles in frontline use. With some M151A2-units still in U.S. military service in 1999, the M151-series achieved a longer run of service than that of the WW2 MB/GPW, M38 and M38A1 series combined.