What Is the Difference Between MPG and MPGe?
When you’re searching for a new vehicle, especially if efficiency is important to you, you will probably come across two different measurements for fuel economy: MPG and MPGe.
MPG stands for miles per gallon. This is pretty straightforward; a vehicle’s MPG indicates how many miles you can drive using one gallon of gasoline. These numbers are always estimates, so you’ll often find disclaimers from manufacturers, reminding you that your MPG will depend on a variety of factors such as weather, the condition of your car, or simply how you drive.
MPGe stands for miles per gallon equivalent. This measurement is designed for vehicles that don’t run solely on gasoline. Hybrid vehicles, a common choice for eco-friendly drivers, use both electricity and gasoline. These vehicles can often go further between stops at the gas station because the electricity is adding to the vehicle’s stamina. Electric vehicles are as simple as they sound: they run solely on electricity.
Now, MPGe technically stands for “miles per gallon equivalent,” so it must be directly comparable to MPG, right? Kind of, but not exactly.
If you’re driving a hybrid car, your MPGe isn’t actually what you can drive on one gallon of gasoline. The Environmental Protection Agency (EPA) calculates your vehicle’s MPGe based on the amount of energy you are using, not necessarily one gallon of gasoline.
The EPA has determined that 33.7 kilowatt-hours of electricity is equal to one gallon of gasoline, in terms of energy. If you’re driving a gasoline-powered car that earns an EPA-estimated 25 MPG and your neighbor is driving a hybrid with an EPA-estimated 115 MPGe, it would require the same amount of energy for you to drive 25 miles as it would for your neighbor to drive 115 miles. Not necessarily the same amount of gasoline.
If you’re focused solely on energy usage, MPG and MPGe are fairly even comparisons. However, if you’re looking at a hybrid and trying to calculate your monthly fuel costs, it’s a bit more complicated than a one-for-one comparison.