Driving around a 5 Ton 6X6. Model M923A2 Military Cargo Truck. The M939 series 5-ton 6x6 truck is a family of United States military logistical transportation trucks which was designed in the late 1970s and remains in service.
These trucks came out in 1982,not in the 1970's.The first variants of the M939's were the ones with G177 (42 inch) dual tires and the NHC-250.When the A1 came out they used the same engine but switched to 48/1400×20 super singles.The same Cummins in them is the same one that all of the M809's came with.Finally when the A2 came about,AM General no longer manufactured them but BMY Harsco did and they were given the 12V 6CT and still had 48/1400×20's but were equipped with CTIS.The A1 & A2 both have the exact same tires but look at the tread,and since the A1 never had CTIS all you have to do is look at the front rims to confirm what series it is because the A2 has wheel guards to seperate the air valves,the A1 doesn't and there aren't any assembles on the axles either.
I just recently bought me a 5ton 6x6. Cummings engine. But I have been shut down now for a week trying to reprime. My engine . But I can get fuel. Up threw my lines an to the bottom part of the injection pump. Just can't seem to get the darn thing to work. I sure could use a helping hand on the lovely truck
But that doesn't have the multi fuel engine! With the miles per gallon it gets you need a fuel tank almost the size of the back of the truck to go very far.
The NHC-250 Cummins in both the early M809's/M939's usually got 3-4 MPG.The 6CT Cummins in the A2's of the M939's made 7-8 MPG. The engines used in the five ton trucks are way better off and power packed than the multi-fuels ever were.The 7.8L only makes 135-175 HP/330-447 TQ depending if it's the LDT-465 or LDS-465,but the 14.0L has 250 HP/658 TQ and the 8.3L is 240 HP/592 TQ. The multi-fuel by the way is just a ignition compression engine with different pistons,pumps,and injectors that allows it to combust gas when mixed at 30% with motor oil or diesel at 70%.The exact same types of oils,diesels,and fluids you could use in a multi-fuel can be used in other diesel engines,the only problem with that is all of the different consistency causing wear on the injectors and fuel pumps.
