How Much Would I Save on Gas with a More Fuel Efficient Car?

Updated on August 5, 2015

Dr. Penny Pincher founded the popular personal finance blog Penny Pincher Journal in 2013 and has published two books about saving money.

How Much Can You Save on Gas?

You can quickly estimate how much money you would save in fuel cost every month by driving a more fuel efficient vehicle. This can be an important factor in deciding whether to keep driving your current vehicle, or whether to get a more fuel efficient vehicle.

This article provides tables to make it easy for you to look up the fuel cost for your current vehicle and your new vehicle so you can see how much you would save in gas money each month.

Find the Fuel Cost of Your Vehicle

Using the tables below, you can get a quick idea of the fuel cost of your current vehicle and the vehicle you are thinking about buying.

Step 1. Choose the table for the amount of mileage your drive- mileage for a typical vehicle is 1,000 miles per month. Tables are provided for low mileage, typical mileage, and high mileage.

Step 2. Select the mpg of your current vehicle and find the fuel cost per month.

You can measure the mpg of your car, or you can check typical fuel economy for your make and model at fueleconomy.gov. Use the mpg on the table that is closest to your vehicle's mpg.

Step 3. Select the mpg of your next vehicle and find the fuel cost per month

Step 4. Subtract the fuel cost of your new car from the fuel cost of you current car to determine the monthly fuel cost savings.

Example

For example, if you drive typical mileage and your current car gets 25 mpg, your fuel cost per month is \$120. If you continue to drive the same distance with a car that gets 40 mpg, your fuel cost per month is \$75.

The fuel cost savings of driving a 40 mpg vehicle instead of a 25 mpg vehicle is:

\$120 - \$75 = \$45 per month

How to Calculate Fuel Cost for Specific Driving Distance and mpg

If you would like a more detailed calculation of fuel costs for your specific driving distance and miles per gallon, use the instructions below.

You can estimate the fuel cost of operating a vehicle with the following information:

1. Cost of fuel
2. Driving distance
3. Fuel efficiency of vehicle (mpg)

Fuel Cost

Let’s use \$3 per gallon as the cost of fuel.

Driving Distance

Mileage for a typical vehicle is 12,000 miles per year or 1,000 miles per month. You can estimate your mileage based on the number of miles you drive the vehicle each day:

Daily Driving Distance x 7 days per week x 4.3 weeks per month = miles per month

For example, if you typically drive 10 miles each way to work, plus 10 miles for errands, your driving distance per month would be:

30 miles per day x 7 days per week x 4.3 weeks per month = 903 miles per month

Gallons of Fuel

Now let’s calculate how many gallons of gas this requires in your current vehicle. Take the miles calculated above and divide by the mpg of your car to get gallons consumed. You can measure the mpg of your car, or you can check typical fuel economy for your make and model at fueleconomy.gov.

Gallons of fuel consumed = Miles per Month / mpg

So, if you drive 903 miles per month and your car gets 23 mpg, your fuel consumption is:

903 miles / 23 mpg = 39.3 gallons

Cost of Fuel

Now for cost of fuel per month: multiply gallons consumed x cost of fuel per gallon

For the example above:

Cost of fuel = 39.3 gallons x \$3 per gallon = \$118 per month

That’s the fuel cost per month for your current car. How much would you save with a different car?

For the new car, we’ll use the same miles per month and fuel cost. The difference is mpg. So for your new car, the fuel cost per month is:

Gallons of fuel consumed (new car) = Miles per month / mpg (new car)

Cost of fuel per month = gallons consumed (new car) x cost of fuel

Let's say your new car will get 43 mpg.

Gallons of fuel consumed = 903 miles / 43 mpg = 21 gallons

Cost of fuel = 22.6 gallons x \$3 per gallon = \$63 per month

Fuel Savings

So in this example, gas for your old car costs \$118 per month and gas for your new car costs \$63 per month. So you would save \$55 per month in fuel costs by trading your 25 mpg vehicle for a 40 mpg car.