Bought this for a new engine after my original GM 5.3 blew because of the AFM system. The devise improved acceleration. I believe it has somewhat decreased MPG but not much. Would rather use a little more gas than have sub par performance and avoid future engine failures because of cylinders shutting down and resulting poor oil circulation.
Not what I was expecting
I'll start by saying I was skeptical. First time using a tuner and I know it should help but never really thought it would be all that noticeable. I used the canned 87 octane tune as I use my vehicle for commute by it really did make a noticeable difference. Much more response with better economy, it's a double win for me. Can't imagine what a 93 custom tune would do for it! If your a first time buyer I would definitely recommend you try it out, you won't be sorry.