Specification Crew : 5 Engine power : 400 bhp Combat weight :18,140 kg (39,998 lb) Max speed : road 80 km/h (49.68 mph) Length : 6.65 m (21.82 ft) Range : 240 km (149.04 miles) Width : 2.97 M (9.74 ft) Main gun : 76 mm(2.99 in) Height : 2.56 m (8.42 ft) Armour : 7 mm (0.28 in)to 12 mm(0.47 in)

In December 1941 the US Armys Tank Destroyer Command proposed a 37 mm(1.46 in)gun-armed vehicle with a torsion bar suspension and an open turret.This was later revised to allow an 75 mm(2.96 in)gun to be carried and then an 76 mm(2.99 in)gun,to keep in step with successive M4 medium tank series armament changes.The final form of a series of experimental vehicles was designated T70 and in July 1943 the T70 became the Gun Motor Carriage M18 and went into production;1000 were initially ordered although by October 1944 when production ceased 2,507 had been built. The M18 was one of the fastest armored fighting vehicles of World War II having a maximum road speed of 80 km/h(49.68 mph).This was mainly due to a combination of light weight,a sturdy Christie-based suspension and a 400 hp(298.4 kW)engine all combining to provide a high power-to-weight ratio.The light weight was partly due to the light armour provided for it was intended that the M18 would utilize its speed and mobility for shoot and scoot tactics;the light armour was partially offset by the arrangement of the sloping armour plates to provide extra protection.Crews named the M18 the Hellcat,although the name was unofficial.It was later rated as the best all-round tank destroyer of World War II.