Figuring out costs is simple when you know the formula. Factor in four major standing, or fixed, costs (depreciation, state fees, financing and insurance) plus three major running costs (fuel, repairs and maintenance). Standing costs usually level out and decrease over time, with finance charges, for example, eliminated when the loan is paid off. Running costs, on the other hand, can increase. As a general rule, the older the car, the more frequent the repairs. Conversely, depreciation on older cars slows, so the increase in running costs can be offset by lower standing costs. Since fuel is the highest running cost, you can save by purchasing a vehicle that gets good mileage and uses regular instead of premium gasoline.