Stewart & Stevenson's Family of Medium Tactical Vehicles (FMTVs) was until recently produced in two main versions: the Light Medium Tactical Vehicle (LMTV) 2.5-ton 4x4; and the Medium Tactical Vehicle (MTV) five-ton 6x6. There is 85% commonality of components and assemblies between the two vehicles.

Originally based on the Steyr 12 M 18 truck, the FMTV has evolved into a vehicle family with payload capacities above 10 tons.

The US Army Tank-automotive and Armaments Command (TACOM) awarded Stewart & Stevenson the first FMTV award in October 1991. It was a five-year, $1.2 billion multi-year contract for 10,843 FMTVs. In October 1998, Stewart & Stevenson was awarded a second multi-year contract valued at $1.4 billion to continue FMTV production. In September 1999, the US Army approved production of the A1 model FMTV.

Following a competition with Oshkosh Truck Corporation, Stewart & Stevenson was awarded the FMTV A1 Competitive Rebuy production contract in April 2003. This contract is worth a potential $2 billion-plus and calls for almost 11,000 FMTVs and trailers over five years, with an option for an additional 12,000 trucks and trailers. Production of the FMTV A1 Competitive Rebuy vehicle (FMTV A1R) is due to commence in the third quarter of 2004.

The FMTV vehicle variants are complemented by 2.5- and five-ton tactical trailers, which were first fielded in September 2001.

The US Army currently has a stated total requirement for 83,000 FMTVs. However, this figure is unlikely to be met as the Future Tactical Truck System (FTTS), currently under development, is scheduled to enter service around 2010-12.

There are currently 20 2.5-/five-ton FMTV variants. The FMTV has also been developed into 10-tonne dump (in production) and eight-tonne LHS (contract pending) variants.

The chassis is also involved in a number of trials/developmental programmes that include cab armouring and hybrid drive systems. An 8 x 8 chassis has been developed to meet part of the UK's 8,500 (approx.) Support Vehicle requirement, for which the FMTV is one contender.

Throughout their production run, all FMTVs have been fitted with a drive-line consisting of a Caterpillar diesel engine, an Allison automatic transmission and Meritor hub-reduction beam axles.