Gas Mileage Calculator

Fill the tank, zero the trip odometer, drive normally, refill at the same pump orientation, and divide miles by gallons pumped. Averaging three tanks smooths out pump-shutoff variance. Dashboard MPG readouts typically flatter by 3–7%.

Under-inflated tires, roof cargo, and speeds above 65 mph each shave several percent; aggressive acceleration is the biggest single factor in city driving. A sudden unexplained drop of 15%+ is worth a mechanic's look — think dragging brakes or a failing oxygen sensor.