What Is MPGe? Comparing Electric Vehicles To Their Gasoline Counterparts
As electric vehicles (EVs) become more popular and widespread, more car shoppers are starting to notice them at dealerships. There are now numerous new vehicles on the market, including all-electric SUVs and pickups. However, the window stickers on new cars can be somewhat confusing unless people are familiar with the concept of MPGe.
It is an energy efficiency metric specific to EVs and is helpful when comparing various vehicles. Whereas an efficient gas-powered car may get 35 or 40 MPG, an efficient EV may have an MPGe of 100 or more.
However, the MPGe is an energy efficiency metric, and it doesn’t provide all the energy-related information regarding EVs. For example, this value does not indicate the driving range of the car, the electricity cost of charging the vehicle, or the battery capacity.
Although efficiency is closely correlated with the operating costs of the vehicle, car shoppers are usually more concerned about the EV’s range. Yet, incorporating vehicle efficiency should also be an important consideration because it relates to the amount of energy the vehicle will need over its lifespan and has financial implications.
Let’s demystify the topic of MPGe and understand why this information is helpful.
What Does MPGe Mean?
MPGe stands for miles per gallon equivalent and is a measurement of the estimated distance traveled with a given unit of energy. It’s useful information for consumers that wish to make more eco-friendly and efficient purchases because it makes it straightforward to compare various models.
The Environmental Protection Agency (EPA) introduced the MPGe concept in 2010 to make it possible to compare an EV’s energy consumption to another EV or a car with an internal combustion engine.
Before developing MPGe, the EPA conducted focus groups to determine the best way to communicate efficiency information for EVs. One finding was that participants didn’t understand kWh as a measurement of energy but could conceptualize the amount of energy in a gallon of gas. Therefore, the EPA created the concept of miles per gallon equivalent.
Now, car dealerships are federally mandated to provide MPGe for EVs and plug-in hybrid electric vehicles (PHEV) and miles per gallon (MPG) for gas-power cars. Thus, car shoppers can learn the MPGe of EVs on the window sticker on all new cars and light-duty trucks.
Likewise, fuel economy.gov is an excellent resource about fuel economy, vehicle range, MPGe, MPG, and even EV tax credits. It also contains a feature that allows users to compare different vehicles with all these data points.
How Is MPGe Calculated?
MPGe is a measurement based on the energy content of gasoline, which is 115,000 British Thermal Units (BTUs) or 33.7 kilowatt hours (kWh) of electricity. Therefore, the value tells you how far an EV can travel using 33.7 kWh. A higher MPGe means the car is more efficient, whereas a lower number indicates it’s less so.
The EPA uses the assumption that a gallon of gasoline has a comparable energy content of 33.7 kWh. Therefore, a car that uses 33.7 kWh to travel 100 miles has an MPGe of 100.
This information is presented differently on the window sticker for PHEVs because these vehicles can run in a battery-powered mode and use an internal combustion engine when the driver depletes the battery. Therefore, they display both MPGe and MPG.
Another measurement of the efficiency of EVs is kWh per 100 miles, which measures how much electricity is needed for an EV to travel that distance. A car with a higher MPGe will require fewer kWh to drive 100 miles.
An EV that can travel using 25 to 30 kWh per 100 miles is efficient, whereas a less efficient model may need 34 or more kWh. There is a similar metric for gas-power vehicles, which is gallons of gasoline per 100 miles.
MPG Vs. MPGe: What’s The Real Difference?
MPGe is merely the electric version of MPG. Whereas MPGe is a wall-to-wheel measurement, MPG indicates fuel-tank-to-wheel consumption. For both metrics, a higher value indicates a more efficient vehicle.
In addition, these metrics highlight how much more efficient EVs are compared to most gas-powered cars, which also helps explain why they are so much cheaper to operate. This is because EVs don’t waste so much energy to heat, and more of their energy is directed toward moving it down the road.
FAQs On MPGe
Because MPGe is a relatively new concept, many people are still learning how to apply it when shopping for an electric car for lower charging costs.
Is MPGe only important for fully electric vehicles?
This metric is only used for battery electric vehicles (BEVs) and PHEVs. Therefore, hybrids that are not plug-ins and gas-powered cars do not have an MPGe rating and only have an MPG rating.
What EVs have the best MPGe rating?
Some of the vehicles with the highest MPGe values for 2022 are the Tesla Model 3, Lucid Air, Tesla Model Y, the Chevy Volt EV, Hyundai Kona Electric, Tesla Model S, Toyota bZ4X, Hyundai Ioniq 5, Toyota Prius PHEV, Kia EV6, and Nissan Leaf. These models have at least a 100 MPGe and are some of the most efficient alternative fuel vehicles. Conversely, some models with an MPGe below 100 are the BMW i4, Volkswagen ID.4, and the Mercedes Benz EQS.
Does MPGe vary depending on city or highway miles?
Yes, vehicles have different values for city and highway MGPe, and these numbers vary. Unlike most gas-powered cars, EVs commonly operate more efficiently when driving in the city compared to highways. Therefore, it is common for models to display an MPGe that is 10 to 30 higher for city driving compared to the highway figure.
How does MPGe impact vehicle operating costs?
More efficient vehicles use fewer kWh of electricity to get from point A to point B. The higher the MPGe, the lower the cost of operating the vehicle when all other factors are equal. However, the cost per kWh of electricity significantly impacts operating expenses, and electricity rates vary widely across the United States. Therefore, the cost of operating a Tesla Model 3 in Hawaii or California, with high electricity rates, could be greater than driving a less-efficient BMW i4 in Washington or Wyoming, where rates are much lower.
Conclusion: MGPe Is A Useful Energy Efficiency Metric
When EV shoppers want to compare the efficiency of various vehicles, MPGe is a helpful figure. The EPA introduced MPGe to help car shoppers make more informed purchases, and a higher value indicates a more efficient vehicle. Therefore, a car with a higher MPGe will be cheaper to operate when all other factors are equal and travel farther from each kWh of charge.
Want to learn more about EVs? Check out our article on charging levels.