MPGe and Efficiency
Electric vehicles don’t use gallons of gas, so how can you measure how efficient they are? The answer is MPGe: Miles Per Gallon of Gasoline Equivalent. It’s the EPA’s way of helping drivers compare the efficiency of EVs and traditional gas-powered vehicles.
This article explains what MPGe means, how it's calculated, how it compares to real-world efficiency, and how you can use this information to make smarter decisions as a buyer or EV owner.
What Is MPGe?
MPGe stands for Miles Per Gallon equivalent. It’s a standardized way to compare the energy efficiency of electric vehicles, hybrids, and plug-in hybrids with gasoline-powered cars.
Instead of measuring gallons of fuel, MPGe is based on how much energy is used to travel a specific distance.
- 1 gallon of gasoline = 33.7 kWh of electricity (as defined by the U.S. Department of Energy)
- If an EV uses 33.7 kWh of electricity to drive 100 miles, its MPGe would be 100
This metric helps drivers understand how efficient an EV is compared to a familiar benchmark, miles per gallon.
How Is MPGe Calculated?
The EPA performs standardized tests using dynamometers (essentially treadmills for cars). The results are used to determine:
- City MPGe
- Highway MPGe
- Combined MPGe (a weighted average: 55% city, 45% highway)
The Formula:
MPGe = (Total Miles Driven ÷ Total Energy Consumed) × 33.7
So, if an EV uses 25 kWh to drive 100 miles, the MPGe would be:
MPGe = (100 ÷ 25) × 33.7 = 134.8
This would be listed as 135 MPGe on the vehicle’s window sticker.
MPGe vs. Real-World Efficiency
EPA MPGe figures are helpful for comparison, but your real-world efficiency may differ depending on:
- Driving speed and style
- Terrain and elevation changes
- Use of climate control
- Vehicle load (passengers and cargo)
- Temperature and weather
To get a more accurate picture of range and energy use, many EVs provide miles per kWh directly on the dashboard. This figure tells you how many miles you're getting per unit of energy used, similar to MPG.
Learn more about real-world range in What Affects EV Range in the Real World?
What Is a Good MPGe?
Most EVs today range from 90 to 135 MPGe. Some compact models like the Lucid Air Pure, Tesla Model 3, and Hyundai IONIQ 6 score well over 120 MPGe.
Higher MPGe means greater efficiency, but it doesn’t always mean greater range. A vehicle with a large battery and slightly lower MPGe may still go farther between charges.
How Does MPGe Compare to MPG?
MPGe helps drivers compare the energy cost of EVs to the fuel cost of gas-powered vehicles. Here’s a simplified comparison:
- Gas-powered sedan:
- Fuel economy: 30 MPG
- Estimated cost per mile: $0.13 (based on $4.00 per gallon)
- Electric sedan:
- Energy efficiency: 120 MPGe
- Estimated cost per mile: $0.04 (based on $0.14 per kilowatt-hour)
Even the most fuel-efficient gas sedans typically cost more to operate per mile than electric vehicles. That’s why MPGe is a valuable tool when evaluating long-term operating costs and savings.
Where to Find MPGe Information
- EPA Fuel Economy Website: fueleconomy.gov
- GreenCars Buyer's Guide: Features MPGe, range, battery size, and more
- Monroney Label (Window Sticker): Found on all new vehicles for sale
Want to compare real-world range and efficiency? Browse side-by-side stats in the GreenCars Buyer's Guide
Final Thoughts
MPGe is a powerful metric that helps level the playing field when comparing the efficiency of electric and gas vehicles. It offers a clear, government-backed measure of how far your car can go using a given amount of energy.
While not perfect, it’s a useful part of understanding EV performance, especially when used alongside other metrics like range and miles per kWh.
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