|

Fuel economy of a new car

Learn what the mpg figures mean

Last updated: February 2014

The fuel-economy figures printed on a vehicle’s window sticker and in automaker advertising and brochures are estimates based on a test created by the Environmental Protection Agency (EPA). For each vehicle, there are two figures:

  • “City” represents urban driving, in which a vehicle is started in the morn­ing and driven in stop-and-go rush-hour traffic.
  • “Highway” represents a mix of rural and interstate highway driving in a warmed-up vehicle, typical of longer trips in free-flowing traffic.

Based on dynamometer testing, these figures provide a way of comparing the gas mileage of different models. All EPA fuel-economy estimates can be accessed at www.fueleconomy.gov and they are also included on the ConsumerReports.org car model pages.

In Consumer Reports’ real-world fuel-economy testing, we’ve found that EPA estimates have typically been higher than you’re likely to get in normal driving. That’s why we conduct several dif­ferent fuel-economy tests of our own, including separate city and highway driving loops. Vehicle speeds and atmospheric conditions are carefully monitored to ensure consistency. Fuel is measured by splicing a fuel meter into the vehicle’s fuel line.

The EPA revised its testing methods starting with the 2008 model year. Additional tests to account for faster speeds and acceleration, air-conditioner use, and colder outside temperatures have been added to the city and highway tests. The EPA has also said that mileage estimates have been adjusted downward to account for wind and road surface resistance, factors that can’t be replicated in the testing procedure.

Regardless of where the original figures come from, a vehicle’s fuel economy is not a constant or fixed number; it depends on driving styles and conditions, and will vary over time.

For more information on saving fuel see our guide to fuel economy including our best cars and SUVs for fuel economy.

New Car Buying Guide

Learn more about choosing a car, what to do at the dealership, pricing, trading in your car, financing, closing the deal and more in our new car buying guide.




   

E-mail Newsletters

FREE e-mail Newsletters!
Choose from cars, safety, health, and more!
Already signed-up?
Manage your newsletters here too.

Latest From Consumer Reports

Audio & video TVs Cats LCD, LED & plasma TVs Electronics Electronics & computers
HDTV REVIEWS
LG 55EC9300 OLED TV falls a bit short of being the best The $3,500 55-inch HDTV displays deep blacks, but minor color flaws too.
NEW CAR REVIEWS
Check out the scary-good car deals for Halloween The big savings you'll find on these models will have you howling.
REFRIGERATOR REVIEWS
7 refrigerator brands that top Consumer Reports' tests These makers have top models in every size, style, and price range.
HDTV ANTENNA REVIEWS
Will cutting the cable-TV cord really save you money? Our TV guy has run the numbers—savings aren't guaranteed.
KITCHEN PLANNING GUIDE
You can remodel your kitchen for as little as $5,000 You don't have to spend a ton to get some of our top-rated appliances.
HOLIDAY GIFT IDEAS & GUIDE
Expert picks: Best holiday gift ideas under $200Video Holiday-shopping season is coming. Find out what to buy.

Connect

and safety with
subscribers and fans

Follow us on:

Cars

Cars New Car Price Report
Find out what the dealers don't want you to know! Get dealer pricing information on a new car with the New Car Price Report.

Order Your Report

Mobile

Mobile Get Ratings on the go and compare
while you shop

Learn more