Consumer Reports’ recent tests of a new generation of fuel-efficient tires found that they not only save gas but are also good all-around performers. Two models it looked at — the Michelin Energy Saver A/S and the Cooper GFE — have low rolling resistance, a quality that can help a car get more miles per gallon.
Rolling resistance, or the force a tire needs to keep it moving down the road, accounts for about 4 percent of a vehicle’s fuel use in city driving and about 7 percent on the highway, according to the Department of Transportation. Replacing high-rolling-resistance tires can result in more than $100 in annual fuel savings.
Automakers often specify fuel-saving tires as original equipment to help a vehicle’s fuel economy numbers. But replacement tires aren’t limited to an automaker’s requirements, and attributes such as all-season grip and tread life are big selling points. In the past, consumers had to weigh a trade-off between low rolling resistance and other performance properties. But in recent years, tire makers have been achieving a better balance between rolling resistance and all-weather grip. And now they’re marketing tires specifically for their claimed fuel efficiency.
In CR’s tests of the Michelin Energy Saver A/S and Cooper GFE, the new formulations seem to be working. Both new tire models fared well. For comparison purposes, CR examined how the two newly tested tires stacked up against 23 other models of T-rated tires it previously rated. In that ratings chart, the Michelin Energy Saver A/S ranked second overall behind the Michelin HydroEdge. The Cooper GFE ranked 11th overall.
CR’s overall score for tires emphasizes safety-related tests including braking, handling, and resistance to hydroplaning. CR also evaluates rolling resistance, ride comfort, noise, snow traction, ice braking, and tread life.
■ Fuel savings from those tires might be appealing, but proper inflation pressure can have a bigger effect on fuel economy, no matter what tires you’re rolling on.
■ NHTSA hasn’t determined a method to present consumer information and will issue a rule at a later date. California is waiting for the federal government to take the lead.
■ CR notes that consumers should be aware that rolling-resistance scores, as proposed, apply to new tires. And if they are not inflated and maintained properly, their fuel-economy benefit disappears.
The nonprofit publication Consumer Reports offers expert ratings of products and services, user reviews, and buying advice. To learn more, visit www.ConsumerReports.org.
COOPER GFE
The Cooper finished midpack in the group. Its rolling resistance was not as low as the Michelin’s, but it performed well in all-weather grip, hydroplaning resistance, and emergency handling.
MICHELIN ENERGY SAVER A/S
It not only had the lowest rolling resistance of any all-season tire CR has tested but also scored “Very Good’’ in dry and wet braking. It ranks second among all T-rated all-season tires.
Efficient choices
What low-rolling-resistance tires save:
■ Of the 200 million replacement tires sold each year in the US only 40 million have good rolling resistance.
■ Replacing high-rolling resistance tires can result in more than $100 in annual fuel savings.
■ If 10 percent of all replacement tires decrease their rolling resistance by 10 percent, that would save 78 million gallons of fuel and 76,000 metric tons of carbon dioxide.
SOURCES: National Highway Traffic Safety Administration, Consumer Reports
