I just got installed the evolution system and it is incredible the power difference on just the lowest setting . One customer towing a trailer recorded a 4 mpg gain on a trip from canada to arizona. The best part is no turbo lag off the line , just a little on the peddle and the van lurrches forward.Plus you get gauge read outs and trouble codes. Will pay for it self in a year if i was on deisel but i run on veggie