Reading the EPA fuel economy label: MPG, MPGe, range and the cost figures

EPA prints a version of the label for each kind of vehicle, identified in its top corner. A conventional hybrid that cannot be plugged in carries the gasoline label, because gasoline is the only fuel it uses; plug-in hybrids and electric vehicles have labels of their own.

On a gasoline label the biggest number is combined MPG, with city and highway MPG beside it. EPA weights city driving at 55% and highway at 45%, and its regulation has the two averaged by fuel used, a harmonic average, rather than by averaging the MPG figures themselves. The combined figure therefore sits a little closer to the lower of the two than a simple weighted average would.

Next to it is gallons per 100 miles, which is 100 divided by combined MPG. It is the better figure for comparing how much fuel two vehicles use, because each extra MPG saves less fuel than the one before: in EPA’s example, going from 10 to 15 MPG saves about 33 gallons every 1,000 miles, while going from 30 to 35 MPG saves about 5.

On this site’s 2027 figures, the median gas-only configuration is rated 22 MPG combined, or 4.5 gallons per 100 miles, and the median hybrid 26 MPG, or 3.8. At EPA’s 15,000 miles a year that gap is about 105 gallons of fuel a year.

Electric and plug-in labels use MPGe, miles per gallon of gasoline-equivalent: the distance the vehicle covers on electricity holding the same energy as a gallon of gasoline, which EPA puts at 33.7 kilowatt-hours. A vehicle that uses 33.7 kWh to go 100 miles is rated 100 MPGe. EPA’s figures include charging losses: they assume Level 2 alternating-current charging and count the energy lost in the charging cable and the vehicle’s on-board charger, so they describe energy drawn from the wall.

For cost, the useful electric number is kilowatt-hours per 100 miles, the counterpart of gallons per 100 miles. It is a rate, not a promise of distance: EPA notes that a vehicle may or may not be able to travel 100 miles on a full charge.

The median 2027 electric vehicle on this site is rated 96 MPGe and 35.2 kWh per 100 miles.

Annual fuel cost is a formula: the fuel price EPA sets for the model year, divided by combined MPG (or, for electricity, miles per kWh), times 15,000 miles, rounded to the nearest $50. The gasoline price is EPA’s figure for that model year, based on projections from the U.S. Energy Information Administration, and it appears in the fine print; electric labels use a projected electricity price.

The five-year line compares that cost with the average new vehicle. EPA multiplies the annual cost by five and sets it against the five-year fuel cost of a gasoline vehicle with average fuel economy, rounding to the nearest $50. A vehicle that costs less shows “You save $X in fuel costs over 5 years compared to the average new vehicle”; one that costs more shows “You spend $X more.” For the 2012 model year EPA’s benchmark was $12,600: a 22-MPG vehicle driven 15,000 miles a year for five years, with gasoline at $3.70 a gallon.

The fuel economy and greenhouse gas rating runs from 1 (worst) to 10 (best) and is based on fuel use and tailpipe carbon dioxide. A gasoline vehicle shows one rating, because its CO2 follows directly from the fuel it burns; other vehicles can show two. EPA puts the line between 5 and 6 at the fuel consumption matching the projected Corporate Average Fuel Economy level for the model year, so a below-average vehicle cannot score above average, and puts the lines between 1 and 2 and between 9 and 10 two standard deviations either side of the mean.

The CO2 line gives the vehicle’s tailpipe emissions in grams per mile, next to the lowest of any vehicle on sale, which is zero whenever an electric or fuel cell vehicle is available. The rating and the CO2 figure count the tailpipe only, not emissions from producing the fuel or the electricity.

The smog rating, also 1 to 10, covers the pollutants behind smog and local air pollution: nitrogen oxides, non-methane organic gas, carbon monoxide, particulate matter and formaldehyde. It is set by the emission standard the vehicle is certified to. A vehicle running on electricity has no tailpipe emissions.

The rest of the label compares the vehicle’s combined figure with the best and worst in its class for that model year (EPA uses nine car classes, six truck classes and a special-purpose class), gives the best combined figure among all new vehicles, and carries a QR code that links to more information about the vehicle on fueleconomy.gov.

An electric vehicle’s label adds two figures. Driving range is the approximate distance on a full charge in combined city and highway driving. EPA derives it by driving the vehicle on a dynamometer over the city and highway cycles until the battery is depleted, adjusting those distances for real-world conditions (most often by multiplying by 0.7), then weighting city 55% and highway 45%. Charge time is how long a fully empty battery takes to charge on 240-volt service; charging from a 120-volt household outlet takes longer.

A plug-in hybrid label shows two fuel-economy boxes: MPGe while running on electricity, and MPG once the battery is depleted and the vehicle runs on gasoline. EPA’s regulation names the first mode “Electric Only” or “Blended Electric + Gas”, depending on whether the engine also runs before the battery is empty, and the second “Gas only”. The label also gives the vehicle’s driving range and charge time, and its annual fuel cost blends the two modes using EPA’s estimate of the share of driving done on electricity.

The median 2027 electric vehicle on this site has an EPA range of 311 miles.

Manufacturers run the tests, following EPA’s procedures, and submit the results; EPA confirms a share of them in its own laboratory. Each test is driven on a dynamometer, which works like a treadmill for cars, following a schedule that fixes the speed for every second.

For the 2007 and earlier model years, only the city and highway schedules were used. From the 2008 model year, three more tests adjust those results for higher speeds, air conditioning and cold weather; together they make up the five-cycle method.

EPA’s test schedules as fueleconomy.gov describes them.

Not every model runs all five. The regulation lets a manufacturer label a vehicle either from its own five-cycle results or, where the vehicle qualifies, from its city and highway results adjusted with equations EPA derived from five-cycle data. Manufacturers may also lower their label values voluntarily if they judge them unrepresentative.

The label says so itself: fuel economy varies with how you drive and maintain the vehicle, how much you use air conditioning and other accessories, the weather, road conditions and how heavily the vehicle is loaded. The test schedules explain part of the gap. The highway schedule tops out at 60 mph and averages 48.3, so a long run at a steady 75 mph is faster than the highway test ever goes. An electric vehicle’s range figure is, in EPA’s word, approximate, and the conditions that change fuel economy change range too.

The fix is to redo the label’s arithmetic with your own miles and prices, as the next section does. Gasoline and electricity prices by state are on the fuel prices page. The cost-to-own calculator does the sums for you.

Here is the arithmetic on real figures. The table takes the median configuration of each powertrain among the 2027 vehicles on this site, with EPA’s annual fuel cost for each as fueleconomy.gov publishes it, at its fuel prices rather than a label’s.

Medians are taken separately for each column, so a row describes no single vehicle.

Over five years, the median hybrid’s fuel costs $250 less and the median electric vehicle’s fuel costs $12,000 less than the median gas-only configuration. That is fuel alone: purchase price, insurance, maintenance and any incentives (state and local programs are listed here) are separate, and the gap grows or shrinks with your own miles and prices.

To work out your own cost, use the label’s formula with your own inputs: miles a year divided by combined MPG, times your price per gallon. At 12,000 miles a year and an example price of $3.50 a gallon, a 22-MPG car costs about $1,909 a year in fuel and a 26-MPG hybrid about $1,615. For an electric vehicle, multiply kWh per 100 miles by your miles divided by 100, then by your price per kWh: at 35.2 kWh per 100 miles and an example 15 cents per kWh, the same 12,000 miles cost about $633. Because EPA’s electric figures include charging losses, that estimate reflects energy bought at the meter.

The most efficient non-hybrid gasoline configuration on file for 2027 is the 2027 Toyota Corolla, rated 35 MPG combined. EPA lists 539 configurations for the 2027 vehicles on this site, and each vehicle page shows its own EPA figures.

• EPA — Text version of the gasoline vehicle label
• EPA — Text version of the electric vehicle label
• EPA — Plug-in hybrid electric vehicle label
• EPA — Fuel Economy and EV Range Testing
• fueleconomy.gov — Detailed Test Information (the five test schedules)
• 40 CFR 600.210-12 — Calculation of fuel economy and CO2 emission values for labeling
• 40 CFR 600.311-12 — Determination of values for fuel economy labels
• fueleconomy.gov — Web services data definitions (annual fuel cost, fuel prices)