Gas Mileage
Just getting used to my new 2019 Fleetwood Discovery LXE 44H. 44 foot diesel pusher towing a Jeep Cherokee. I am averaging about 7.7 miles per gallon. I believe this is pretty normal but just wonderin...
Forum Discussion
A mechanic told me, DEF allows Cummins to tune for better mileage. Non DEF motors were more tuned to satisfy the EPA and less for mileage. Diesels built in the 80's and 90's were pretty fuel efficient though. I have owned both and won't say what I get because the naysayers wouldn't believe it. Although I bet your mileage will get better after break in.
