New EPA Gas Mileage Estimates
From 2008 new EPA gas mileage estimates have been introduced by the U.S. Environmental Protection Agency (EPA). Together with the U.S. Department of Energy (DOE) they produce the Fuel Economy Guide to help car buyers when choosing the most fuel-efficient vehicle that meets their needs.
You are probably not the first new car owner who discovered that the fuel economy estimates found on the window sticker are not quite the same as the mileage you get in real-world driving.
Why new standards?
The fuel economy estimates were too optimistic. Beginning with the 2008 model year, they have introduced a more accurate method for estimating fuel economy.
So it was necessary to replace the old test because the cars as well as the driving have changed a lot in the 40 years since testing began. We drive at higher speeds on the highways, we have cars that can accelerate rapidly and modern cars carry plenty of accessories that consume energy.
The mileage estimates found on 2007 and older cars were determined using test procedures that were developed when this car was new and the driving environment was much different from today. Especially for the new hybrid cars and trucks the fuel economy ratings were unrealistic.
How to compare old cars and new ones?
The revised EPA tests may make it a bit harder to compare an old car with old test data to a newer car of the same make and model that was subject to the new tests. Under the new system, most cars will carry a significantly lower number than before.
This could create some confusion because you expect better numbers for a newer car don’t you? In the right sidebar you can find a simple EPA mileage calculator. Try it!
How does EPA test car fuel economy?
The following factors can lower your vehicle’s gas mileage:
- Aggressive driving (hard acceleration and braking)
- Excessive idling, accelerating, and braking in stop-and-go traffic
- Cold weather (engines are more efficient when warmed up)
- Driving with a heavy load or the air conditioner running
- Improperly tuned engine, dirty air filter, under-inflated tires
The tests are run in a controlled lab environment and cover different cycles that approximate driving in an urban environment, idling time, and high speed traffic. Add to that aggressive accelerations and the use of airco among other variables.
The fuel economy guide is published in print and on the Web at www.fueleconomy.gov.
Each vehicle in this guide has two fuel economy estimates:
A city estimate that represents urban driving, in which a vehicle is started in the morning (after being parked all night) and driven in stop-and-go traffic
A highway estimate that represents a mixture of rural and interstate highway driving in a warmed-up vehicle, typical of longer trips in free-flowing traffic
For the car buyer all that matters is that the new EPA gas mileage estimates are realistic. Remember that mileage will still vary based on your driving behavior and the road conditions.
Category: Gas Mileage Chart Comment »