I have a fully loaded Laramie Crew 4x4, w/3.92 rear end, I Have been hand calculating my gas mileage since August. View attachment. I simply put in date, kilometers at fillup, litres to fill, and it calculates MPG, averages, Best, worst, etc. And its color co-ordinated for a quickview, Red=Bad, Yellow=OK, Green=Good. The O/C SYN. means Oil Change Synthetic.