Fuel Savings Calculator
Weighing a thirsty car against a frugal one? Drop in both MPG figures, your yearly mileage, and the pump price, and see the gas gap between them over a year and over five.
Compare two cars on fuel alone
Two cars, two MPG figures, same yearly mileage and gas price. See how much the thriftier one saves you over a year — and yes, the number can be negative if car B drinks more.
Annual savings with Car B
$645
Car A's yearly fuel minus Car B's
Car A fuel per year
$1,750
500 gallons
Car B fuel per year
$1,105
316 gallons
Savings over 5 years
$3,224
Same driving, five years running
Turning MPG into dollars
MPG on its own is abstract. Wrap it in your actual mileage and local fuel price and it becomes real money. For each car the tool works out the gallons you'll burn in a year, prices them at the pump, and shows the difference.
Picture a 24 MPG crossover next to a 38 MPG sedan, both driven 12,000 miles at $3.50 a gallon. The crossover drinks about $1,750 of fuel a year, the sedan about $1,105 — a $645 gap. Stretch that to five years and you're looking at more than $3,200 in fuel alone.
Use it to sanity-check whether a fuel-sipper's higher price pays for itself, or whether that gap is smaller than the salesperson made it sound.
Frequently asked questions
How is the yearly saving worked out?
For each car, miles divided by MPG gives gallons burned, times the fuel price gives yearly cost. Subtract car B's cost from car A's and you've got the saving. If car B is thirstier, the number goes negative — that's the extra it'll cost you.
Does a jump from 20 to 30 MPG save a lot?
More than you'd guess. Over 12,000 miles at $3.50 a gallon, 20 MPG burns about $2,100 in fuel while 30 MPG burns roughly $1,400. That's around $700 saved a year, and $3,500 across five years of the same driving.
Why do small MPG gains matter less at the high end?
Fuel cost drops on a curve, not a line. Going 15 to 20 MPG saves far more gas than 40 to 45 MPG, even though both are a 5 MPG bump. The thirstier the car, the more each extra mile per gallon is worth.
Can I use this for a hybrid versus a gas car?
That's a great use for it. Put the hybrid's combined MPG in one slot and the gas car's in the other. Just remember the fuel saving is only part of the picture — price, insurance, and resale matter too.
What fuel price should I enter?
Use what you actually pay locally, then try a higher number to stress-test it. If gas spikes, the more efficient car saves you even more, so it's worth seeing how the gap widens at $4.50 or $5 a gallon.
Does driving style change the result?
It can, quite a bit. The MPG on the window sticker is a lab average; heavy city traffic, a lead foot, or lots of short trips pull real-world numbers down. Enter the MPG you truly get for the most honest comparison.