Yeah when I had the non-compliant tune I was every other tank. Was going 400-500 miles per week so about 800-1000 miles.I have non-compliant GDE tune, and mine does not regen that frequently. At 400 miles per cycle, that would be a regen for every tank of fuel assuming approx. 600 mile range. I'm guessing mine is closer to 900-1000 miles or conservatively every other or every third tank.