This little device saved my truck. I was COMPLETELY dissatisfied with the easy the truck ran when the AFM system kicked in. Now, I feel like I'm actually driving a TRUCK!!! As far as gas mileage is concerned, I didn't buy a V8 truck to get good gas mileage, so not worried about that. I will say, though, I haven't noticed much of a decrease.
A MUST BUY!
If you are thinking of buying this product you need to do it. I waited wayyy to long, pondered over reviews and finally pulled the trigger. Dont waste your time with anything else. I turned off the AFM and torque management, 87 octane tune, raised driving idle by 100 rpms and park rpms by 50, with firm shifts. It now drives like the V8 beast I bought, not a Prius...a must have for your truck!