Yesterday on Easter Sunday, my wonderful Acura TSX had it’s first birthday. 21097 miles later, the car runs just as well as the day I purchased it, however the exterior has been subjected to typical Pennsylvania construction plagued highways and encountered a few paint chips along the way. Over the past year I have compiled the mileage data for fuel mileage, as well as a comparison to what the Navigation trip computer says was my average versus what I calculated from the pump and odometer data. What I found is that while the Navigation system was close, more often than not it was on the high side with regards to mileage, which averaged over the 70 tanks to being about 1mpg difference between the two calculations. Pretty good, but the difference is probably how the Navi calculates fuel mileage versus my basic miles / gallons calculation. You can see the data here.