Compare fuel costs on your own mileage.

Give the comparison the same job

Start with your expected annual miles. Use your own recent driving records if they reflect the coming year. Then look up the exact engine, drivetrain, and model year in the DOE/EPA comparison tool. Treat its test figures as comparison inputs, not a guarantee for your route.

For a gasoline car, the basic equation is annual miles ÷ mpg × price per gallon. At an assumed 12,000 miles, 30 mpg, and $3.50 per gallon, that is 400 gallons and $1,400 per year. At 40 mpg with the same assumptions, it is 300 gallons and $1,050. The difference is $350, not the price of a different car.

Use the right unit for electric cars

For an EV, use annual miles ÷ 100 × kWh per 100 miles × price per kWh. With an assumed 12,000 miles, 30 kWh per 100 miles, and $0.18 per kWh, the simple estimate is $648 per year. Check the measurement’s treatment of charging losses and add any applicable session or parking fees.

MPGe is an energy-equivalence measure; it is not your electricity bill. The DOE/EPA EV overview is a useful introduction before comparing gasoline and electric alternatives.

Test a less favorable scenario

Repeat the worksheet with higher energy prices, more highway driving, or more public charging. Label every assumed value. A narrow saving under one set of inputs should not be presented as certain savings over several years.

Maintenance also matters: DOE/EPA guidance discusses tire pressure and the specified oil grade. Use our maintenance plan to organize upkeep, and our EV guide to think through charging access. Keep purchase price, insurance, and repairs in separate budget rows so an attractive energy figure does not stand in for total ownership cost.