Fuel Efficiency Calculator

Let's figure out what you're really spending on gas. Compare vehicles, plan trips, and see if that fuel-efficient car is actually worth it. Real numbers, no BS.

Quick Fuel Cost Calculator

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Your Fuel Cost Breakdown

Ready to Calculate Your Fuel Costs?

Fill in your driving details above and see exactly what gas costs you.

How This Calculator Works (And Why Others Don't)

Most fuel calculators just multiply miles by MPG. That's fine for rough estimates, but real-world driving is more complex. We factor in city vs highway driving, traffic conditions, seasonal changes, and actual gas prices.

What We Include

  • • Real-world driving conditions
  • • City vs highway MPG differences
  • • Seasonal fuel efficiency changes
  • • Local gas price variations
  • • Vehicle comparison tools

What Most Calculators Miss

  • • EPA MPG is lab tested (not real world)
  • • Gas prices vary by location/state
  • • Driving habits hugely impact efficiency
  • • Seasonal changes affect mileage
  • • Total cost of ownership

MPG: What It Really Means

City vs. Highway MPG

"City driving means lots of stopping and starting, which kills your mileage. Highway driving is steady, so you get better MPG. Your car's sticker shows both because they can be wildly different."

Example: A car rated 30 MPG combined might get 27 MPG city and 35 MPG highway.

Why Your Actual MPG Doesn't Match the Sticker

"Those EPA numbers are from controlled lab tests. Real-world driving includes traffic, hills, A/C blasting, and that lead foot of yours. Most people get 10-20% less than the sticker says."

Pro tip: Use your trip computer's MPG for more accurate calculations.

Improve Your MPG Without Buying a New Car

Immediate fixes (free):

  • • Stop idling—seriously, turn off the engine
  • • Remove roof racks when not using them
  • • Lighten your load (that bag of concrete in your trunk)
  • • Coast to red lights instead of braking hard

Cheap fixes ($50-$100):

  • • Check tire pressure monthly (under-inflated tires kill MPG)
  • • Replace air filter ($10-20)
  • • Use the right motor oil
  • • Get a tune-up if you're way overdue

Driving habits that matter:

Accelerate gradually (pretend there's an egg under the pedal), use cruise control on highways, combine errands, and stop speeding—80 MPH uses 20% more gas than 65 MPH.

Frequently Asked Questions

Is premium gas worth it?

Only if your car requires it (check your manual, not the gas station attendant's opinion). If your car says "recommended," regular is fine. You're not hurting your engine, and premium doesn't give you better MPG unless your engine specifically needs it.

Does cruise control really save gas?

On flat highways, yes—about 7-14%. On hilly roads, sometimes it's better to do it manually because cruise control will gun it uphill. Use your judgment.

How much does AC affect my mileage?

About 10-20% in city driving, less on highways. But rolling down windows at highway speeds creates drag, which also hurts MPG. Above 45 MPH, AC is actually more efficient than open windows.

Why is my winter MPG so much worse?

Cold air is denser (more drag), engines take longer to warm up (inefficient), winter gas blends have less energy, and you're running the heater. It's normal to lose 10-15% in winter.

Are those "fuel-saver" devices on Amazon legit?

Almost all of them are scams. If something actually improved MPG significantly, car manufacturers would already be using it. Save your money.