In the late 1930s the US Army began setting requirements for custom built tactical trucks, winning designs would be built in quantity. As demand increased during WWII some standardized designs were built by other manufactures.

Most trucks had gasoline (G) engines until the early 1960s, when multifuel (M) and diesel (D) engines were introduced. Since then diesel fuel has increasingly been used, the last gasoline engine vehicles were built in 1985.

Most engines have been water-cooled with inline (I) cylinders, but V types (V) and opposed (O) engines have also been used. Three air-cooled engines were used in two very light trucks. Gasoline engines up to WWII were often valve in block design (L-head), during the war more overhead valve (ohv) engines were used, and after the war all new engines (except 1 F-head and 1 Overhead camshaft (ohc)) have been ohv. All diesel engines have ohv, they can be naturally aspired, supercharged (SC), or turbocharged (TC).

The same engines have been used in different trucks, and larger trucks often have had different engines during their service life. Because of application and evolution, the same engine often has different power ratings. Ratings are in SAE gross horsepower.

The front of an engine is the fan end, the rear is the flywheel end, right and left are as viewed from the rear, regardless of how the engine is mounted in the vehicle. Engines in the tables are water-cooled and naturally aspirated unless noted.

AM General/Kaiser Jeep/Willys Model Displacement Fuel Type Power Torque Used in AO-42 G AC O4 @3200rpm @2100rpm M274 -ton 4x4 "Mule" AV-108-4 G AC V4 @3600rpm @2500rpm M422 4x4 "Mity Mite" MB G I4 @4000rpm Willys MB/Ford GPW -ton 4x4 "Jeep" MD G I4 @4000rpm @2000rpm M38A1-ton 4x4 Tornado G I6 @4000 @2000rpm M715 -ton 4x4

Caterpillar Model Displacement Fuel Type Power Torque Used in 3116 D TC I6 @1550rpm M35A3 -ton 6x6, Family of Medium Tactical Vehicles C7 D TC I6 @2400rpm @1400rpm Family of Medium Tactical Vehicles C15 D TC I6 @1800rpm @1200rpm M977 (HEMTT), M1074/M1075 (PLS) C18 D TC I6 @1300rpm @1400 M1070A1 (HET)

Chevrolet – GMC Model Displacement Fuel Type Power Torque Used in 6.2L/6.5L D V8 @3400rpm @2000rpm M1008 -ton 4x4 (CUCV), M998 -ton 4x4 (HMMWV) 270 G I6 @2750rpm @1400rpm GMC CCKW 2-ton 6x6, DUKW 2-ton 6x6 amphibian 302 G I6 @3200rpm @1200rpm M135 2-ton 6x6 BV-1001 G I6 @3100rpm @1000rpm Chev. G506 -ton 4x4

Continental Model Displacement Fuel Type Power Torque Used in AO42 G AC O2 @3000rpm @2300rpm M274 -ton 4x4 "Mule" L-142 G I4 @4000rpm @1800rpm M151-ton 4x4 LDT465 M TC I6 M35 2-ton 6x6, M54 5-ton 6x6, M656 5-ton 8x8 R22 G I6 @2400rpm @1200rpm M1 10-ton 6x6 Wrecker R6602 G I6 @2800rpm @1200rpm M54 5-ton 6x6

Cummins Model Displacement Fuel Type Power Torque Used in 6CTA8.3 D TC I6 @2100rpm @1500rpm M939 5-ton 6x6 NH250 D I6 @2100rpm @1500rpm M809 5-ton 6x6), M939 5-ton 6x6 NTC400 D TC I6 @2100rpm @1500rpm M915 series 6x4, 6x6, 8x6 V8-300 D V8 @3000rpm @2100rpm M123/125 10-ton 6x6

Detroit Diesel Model Displacement Fuel Type Power Torque Used in 3-53 D SC I3 @2800rpm @1500rpm M561 -ton 6x6 "Gamma-goat" Series 60 D TC I6 @2100rpm @1200rpm M915 series 6x4, 6x6, 8x6 8V92TA D TC V8 @1200rpm M911(C-HET) M977(HEMTT), M1070(HET) 12V71 D SC V12 @2500rpm @16000rpm M746 -ton 8x8 (HET)

Dodge-Fargo Model Displacement Fuel Type Power Torque Used in T-202 G I6 @3000rpm VC -ton 4x4 T-214-245 G I6 @3200 @1200rpm Dodge WC -ton 4x4, M37 -ton 4x4 318 G V8 @4000rpm @2400rpm M880 -ton 4x4 (CUCV)

Ford Model Displacement Fuel Type Power Torque Used in GTB G I6 @3000rpm @1200rpm -ton 4x4

Hall-Scott Model Displacement Fuel Type Power Torque Used in 440 G I6 @2000rpm @1200rpm M25 tank transporter

Hercules Model Displacement Fuel Type Power Torque Used in DFXE D I6 @1600rpm @1200rpm M19 tank transporter HXD disp G I6 @2150rpm @900rpm 6-ton 6x6) JXD G I6 @2400rpm @1200rpm US6 2-ton 6x6 L-142 G I4 @4000rpm @1800rpm M151-ton 4x4 LDT465 M TC I6 M35 2-ton 6x6, M54 5-ton 6x6, M656 5-ton 8x8 RXC G I6 @2200 @1000rpm Diamond T 4-ton 6x6, Autocar U8144T 5-/6-ton 4x4

International Harvester Model Displacement Fuel Type Power Torque Used in GRD-214 G I6 @3400rpm @1200 IHC M-1-4 -ton 4x4 GRD-233 G I6 @3400 @800 IHC M-1-4 -ton 4x4, IHC M-5-6 -ton 6x6

LeRoi Model Displacement Fuel Type Power Torque Used in T-H844 G V8 @2600rpm @1700rpm M123/25 10-ton 6x6

Mack Model Displacement Fuel Type Power Torque Used EN532 G I6 @2400rpm Mack NJU 5-ton 6x6 EY G I6 @2100rpm @800rpm Mack NM-6 6-ton 6x6, Mack NO -ton 6x6 ENDT673 D TC I6 @2100rpm M54 5-ton 6x6)

REO Model Displacement Fuel Type Power Torque Used in OA-331 G I6 @3400rpm M35 2-ton 6x6

Notes

References

Works cited