The Oshkosh M1070F HET, much revised M1070E1, has the same basic chassis and axle set-up as the M1070 model, but the cab, engine and transmission were changed to meet the European Emission requirements (EURO III).
The 1070F uses a modern Caterpillar 4-stroke diesel engine with 700hp, whereas the earlier models use an archaic 500hp GM 2 stroke diesel engine. The 1070F has a 7-speed Allison automatic transmission with a single speed axle setup whereas the earlier models have a 5-speed Allison automatic transmission with a 2-speed axle setup. More power, more driving range, less maintenance and simplified driver training have to be significant improvements. I suspect that the original power pack and transmission were a necessary compromise in order to replace outdated equipment within a relatively short timeframe. Practicality appears to have won with the original U.S. procurement.
