Tire Rack tests low rolling resistance tires

Sept. 22, 2009

Tire Rack today released results of its report analyzing the effectiveness of eco-friendly, low rolling resistance (LRR) tires.

Following a recent test at its South Bend, Ind., test track, Tire Rack confirms that "using LRR tires is an effective way for consumers to save money while reducing carbon emissions through increased fuel efficiency."

Tire Rack conducted the test after recognizing that a number of tire manufacturers were releasing LRR tires targeted to a group of consumers who were looking at ways to achieve maximum fuel economy while contributing to a cleaner environment. These consumers “are interested in doing things that will maximize mpg’s instead of lateral g's," says John Rastetter. Tire Rack's director of tire information.

The company conducted what it calls a “Real World Road Ride Economy Run” to determine whether lower rolling resistance tires are effective at increasing fuel efficiency. The test, which used a small fleet of Toyota Prius hybrids outfitted with the Goodyear Integrity all-season radial tires as a baseline, compared its fuel efficiency and traction to other eco-friendly and standard tire models.

Each tire was driven over 550 miles on a 6.6-mile loop of public highways around Tire Rack’s facility, which included expressways, highways and side roads where the average speed limit is 40 mph. It’s what real drivers would encounter in their daily lives, Rastetter points out. The Prius outfitted with the baseline tire achieved 51.4 miles per gallon.

Tire line:                                            Test mpg          % vs. baseline

Michelin Energy Saver A/S              53.8                  +4.74%

Bridgestone Ecopia EP100            53.5                  +4.12%

Yokohama dB Super E-Spec          52.8                 +2.81%

Goodyear Assurance Fuel Max       51.6                 +0.37%

Goodyear Integrity                              51.4                 ----

Michelin HydroEdge with Green X   51.1                 -0.59%

Goodyear Assurance ComforTred     50.0              -2.64%

In the case of the Prius, Tire Rack reports, the difference between the lowest and highest recorded miles per gallon would result in an annual difference of about 21 gallons of regular gasoline consumed at a cost of about $52.50 (at $2.50/gallon) for drivers traveling 15,000 miles a year.

The Prius was chosen because it is the “most popular fuel efficient vehicle in the U.S.” Rastetter, says. When you apply the results to other vehicles, the percentage differences in fuel economy stay the same, but the dollar differences will be even greater, he points out.

“Low rolling resistance tires represent the most environmentally focused development in tire technology today,” says Rastetter. “Every gallon of gasoline saved not only reduces each driver’s personal fuel costs and America’s dependence on foreign oil, but it also releases 20 fewer pounds of CO2 gas into the atmosphere from the tailpipe. Our tests proved that vehicles equipped with these tires can achieve better fuel economy.” 

While the low-tech ways of achieving lower tire rolling resistance has usually traded off wet traction and/or tread wear, further controlled testing at Tire Rack’s test track has also shown that the newest high-tech, fuel-efficient tires have achieved it without compromising traction thanks to the introduction of new tread compounds, tire designs and weight optimizing manufacturing processes.

According to newly passed governmental Corporate Average Fuel Economy (CAFÉ) standards, new vehicles will need to achieve 35.5 miles per gallon by 2016. As automakers reevaluate every aspect of their vehicles in order to increase fuel efficiency, fitting their vehicles with LRR tires is an easy first step.

“While tires have always played an important role for all types of drivers, our test results show tire manufacturers have successfully added some green to the traditional round and black,” says Rastetter.

For more information, visit Tire Rack’s Web site at www.tirerack.com/mpgtest.