Great to hear it! After going 100% Mobil-1 in the Dragon it averaged a consistent 2 MPG increase. I started changing over as each service item came due from new, although I did the tranny a bit early out of impatience. When I got the IronMan I pretty much did everything across the board to 100% Mobil-1 since it had 99,500 miles when purchased. Now I'm at 106,000 and just got 21MPG highway on a recent road trip. Darn thing is peppier and more efficient than the bought-new Dragon! Oh well, it's an Isuzu... they just get better with age! ;pg;