Occasionally -- every month or so -- the computer acts as though I've reset the mileage calculation. I'll be midway through a tank of gas -- have driven 150 miles or so -- and the trip computer (not trip odometers, they remain correct) will report that I've driven 11 miles or whatever, and the history (previous gas tank's mileage) will be missing. Nobody else drives the car, the gas tank lid hasn't been opened, etc.

FWIW, the nav system computer was defective when I took delivery, was replaced in the first month. But this weird behavior is relatively new, has only been the last six months or so.

 

hmm , there good be a short some where that resets it...

 

Yeah, I'd thought of that. An intermittent short, great -- that will be fun to convince the dealer to believe, and if they do, fun for them to fix.