From the time I bought it, until earlier this year when I learned to reset the screen, I got an over average of 16.4. After resetting it, it didn't vary much from that. City, between 12.5 - 15.5 mpg, highway up to 19.5. Now I've put BFG A/T's on it in a larger size and it shows that I average around 15 - 15.5 mixed driving. I didn't replace the speedo gear, and am not going to, so I'm pretty sure the mpg & speedometer will not read correct, but close enough for me. I just got back from Oregon and the last leg of the trip was 350 miles (according to the trip odometer) and I put in 22 gallons. If the new tire size makes that much difference, then the 350 miles is not correct. Oh, and most of those highway miles were at 75 - 80 miles per hour. I'm sure if I took it easy on the skinny pedal and kept it at the posted limit my mileage would improve.