Dude, I usually get about 25 mpg, or did when my car was stock(er) than it is now. I wonder if my VAFC is causing my shmiz to run rich, or if the settings are no longer doing anything(ECU has switched them back)? But when I went to fill up my car yesterday, I needed 6 gallons for 139 miles of daily drivng, and most of it was not hard either. I don't have an AF gauge hooked up to see either, but something doesn't seem to be working right on my car if this is the mileage I'm getting. How EXACTLY do you check spark plugs(get them out, and get them back in correctly- tools needed, etc.)