|

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

SMART PHONE REVIEWS
Save up to $1,000 with the right cell phone plan Plus, our three tips to figure out how large a data plan you need.
Electronics
HOLIDAY GIFT IDEAS
Survey: Worst holiday gift to give isn't a pair of socks A few items, including booze, make for bad presents.
SMART WATCH REVIEWS
High-tech holiday gift: 4 best smart watches of 2014 Style and function put these wearable devices ahead of the pack.
CAR MAINTENANCE GUIDE
Holiday shopping: Low-cost gifts for car loversVideo These presents for gearheads won't break your budget.
PAPER TOWEL REVIEWS
6 ways to spiff up your house before the holidaysVideo Stock up on cleaning supplies and make room in the refrigerator.
COFFEEMAKER REVIEWS
Must-have kitchen gear and appliances for $100 or less Check out these standout blenders, mixers, coffeemakers, and more.

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