Gas out here in SUNNY SOUTHERN CALIFORNIA for 91 octane ( thats all they have out here hi-octane wise ) is $2.27 a gallon and rising. As for mileage, on a ratio of about 80% freeway and 20% street, I average about 28mpg. Of course I have the POWERCHIP GOLD 91 software upgrade and I just can't say enuff about it. Horsepower increase of 15HP and great gas mileage, I am diggin' it. I've read about the UPSOLUTE software upgrade, but I am quite happy with my POWERCHIP software upgrade. POWERCHIP is a bit more dollar wise ( $150-$200 more ), but maybe they will go down in price seeing that their is a new kid in town. Also, POWERCHIP already modifies Mercedes-Daimler cars, so it is nothing new for them. Last I heard from them is they are still trying to go thru Daimler-Chrysler to officially be the updaters. Don't know the final story.