Is bad gas mileage a good enough reason to purchase a new vehicle? I’ve wrestled with this question many times. The real question comes down to whether gas mileage is a valid reason to purchase a new vehicle, or if it’s simply a justification for wanting a new vehicle? Let’s take an in-depth look at this question—with the help of a little math.

There are a few factors to consider in determining if selling a vehicle in order to purchase a more fuel efficient one is a worthy trade-off—the price of gas, your current gas mileage and the prospective car’s gas mileage. Let’s also add in annual gas mileage to get a full picture of the savings associated with buying a more fuel-efficient vehicle.