Reason I ask, is that I took my truck in for regular oil change, tire rotation etc. . and It took them longer than usual to get me out of there. I left on a trip that same day pulling the horse trailer and my mileage went up 2-3 MPG almost instantly. Ever since, my read out is Higher and my Hand calc is matching it... Maybe I should go look for a sticker??? I did re-check my paperwork and nothing is listed on the paperwork regarding a reflash. ROper