very good question......I just changed back to the stock turbo for this resaon. On my truck, with 37s and lifted... i noticed that at low throttle it was runing hotter than stock and that on normal driving...flat on cruse controle.. that the boost was lower and the motor ran hotter. Clearly on a hill or high throttle or pulling a trailer the larger turbo was better,cooler, more boost. It it my conclusion that it takes more to spool a bigger turbo, and be more i mean throttle. my truck seams to do 1.5 - 2.0 mpg better with stock turbo empty no or very little load. In ust a slight head wind the turbo spools and i get boost ware i dont with a 62 - 12. So to anser your question yes i think boost is good. your fueling the motor eather way , but win its boosting it makes more power = better milage.........Well maybe 2 cents