6.4 Hemi Trucks

Hey Dylan, all i can tell u is my experiences. My 03 and 07 with all the deletes and programmer (5.9) had absolutely the best mpg.my 2012 (6.7) pre d.e.f. truck had the emission deletes and a programmer was horrible no matter how i drove.my buddies late2012 with the d.e.f. got 4 mpg BETTER than mine all the time and his is stock.Steve