Since you wanted feedback from actual users, here it goes. The best thing about AFE that I have noticed is that the Tacoma feels different. It seems to rev freer, it is quieter right after startup, after the initial warmup the engine seems happier to perform any chore, from lugging along at 1300 RPM's in higher gears on KC's long boulevards, to hauling 1300 lb loads. As far as fuel mileage goes, I have a Ultragauge, and while the seasons here make a big difference in fuel mileage here in KC, with the help of the Ultragauge I believe my mileage is a solid 1 MPG better than when using a 5w-20 or 5w-30. Not scientific findings but a genuine seat of the pants observation. My current fill is the last of my AFE and I have a large stash of other oils to use and they are all 5w-xx, some dino and some syn. We will see if the Tacoma likes them as much as the AFE. I initially bought AFE because I always want to try a 0w-20 and AAP they had a Black Friday specail for $3.99, so I gave it a try.