I am going to toss in my 2 cents of information. It is my understanding the JWAC was designed to maintain a constant temperature of the air entering the engine from the turbocharger. On the flip side of what everyone is currently looking at is that part of the design is to increase the air temperature entering the engine permitting the engine in a stationary application to decrease warm up time. For example if you have an engine mounted on a wood chipper and it's twenty degrees outside the warm up time to operate the chipper is decreased so productivity of the crew using it increases. So why did the early Fritos vans have the JWAC? I don't know other than the usual unit standardization, availability and price at Cummins verses the demand by Fritos. Remember that this is an industrial designed engine adapted for automotive use.