Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.
Bone stock, AFM helps a little. But with the optimization justin does with the tuning in both the engine and the trans, some people see better results with it turned off. Everyone's situation is different and a lot depends on your driving style, location, and truck.
Personally, I'm beginning to wish that I had gotten it turned off. With all of the problems I'm having w/ my Airaid intake, I might get a re-tune with a different intake and have him turn AFM off at the same time.