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My understanding is that the reason for the lower ratings for the diesel in the van chassis is that there was no room to fit an intercooler. If so, that's going to limit any significant increases in BHP because of excessive EGTs. That may be why there's not a lot of aftermarket support for this chassis.
Insofar as fuel efficiency is concerned, if your injection timing is retarded for emissions reasons as it was on my Cummins HO, a timing only box/chip could help gain maybe 1-2 MPG. I wouldn't want to add any additional fuel because (1.) if you have the extra power, you'll use it (ask me how I know
), and there goes any fuel economy gain, and (2.) more fuel will drive up EGTs, which you don't want.
2016 Ram Longhorn 3500 Dually 4x4 CCLB, 385/900 Cummins, Aisin AS69RC, 4.10
2014.5 DRV Mobile Suites 38RSSA #6972
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