Fuel savings calculator

See how much a more efficient car would save you in gas.

mpg
mpg
mi/yr
$/gal

How fuel savings are calculated

Current annual cost = (Miles ÷ Current MPG) × Gas price

New annual cost = (Miles ÷ New MPG) × Gas price

Savings = Current cost − New cost

The MPG improvement that matters most

Here's something counterintuitive: improving from 15 to 20 MPG saves more money than improving from 30 to 40 MPG. That's because fuel consumption isn't linear — each MPG point matters more at lower numbers.

At 12,000 miles/year and $3.50/gal:

15 → 20 MPG saves $700/year
20 → 25 MPG saves $420/year
25 → 30 MPG saves $280/year
30 → 40 MPG saves $350/year
40 → 50 MPG saves $210/year

This is why upgrading a gas-guzzling truck to something more efficient can save dramatically more than upgrading an already-efficient sedan.

Before you buy: factor in total cost

Fuel savings alone don't always justify buying a new car. Consider the full picture:

  • 💰 Purchase price difference. If the more efficient car costs $5,000 more and saves $500/year, the payback period is 10 years.
  • 📉 Depreciation. Your biggest car cost is usually depreciation, not fuel. A 3-year-old efficient car often makes more financial sense than a brand new one.
  • 🔧 Maintenance costs. Hybrids and EVs have lower maintenance costs. Factor in oil changes, brakes, and other services.

Free ways to improve your current car's MPG

Before buying a new car, try these zero-cost improvements:

  • Check tire pressure. Properly inflated tires improve MPG by up to 3%.
  • Drive smoother. Gentle acceleration and coasting to stops can improve MPG by 10–20%.
  • Use cruise control. It saves 7–14% on the highway.
  • Remove unnecessary weight. Clean out the trunk. Every 100 lbs costs about 1% MPG.

Track your improvements with our MPG calculator.