I have a 13 with the 5.0. Had it a little over a year. Gauge says 18.0. I was manually checking for the first few months, and the gauge was so close as to make that a waste of time. But, I do drive like your grandma. Can't remember the last time the gas pedal hit the floor. Not a lot of towing. I pull the concession trailer about 10 times a year, and we took the flatbed loading with camping and hunting gear to Canada last year.