I pondered this thought as I drove in rain-soaked New York streets with my tester Mitsubishi Mirage while worrying about hydroplaning. Luckily I didn’t. And luckily, Michael Sivak of the University of Michigan Transportation Research Institute helped crunch the numbers from Consumer Reports’ raw test data of low rolling resistance tires. A full article is available, but you can get what you need to know from their abstract:
This study was designed to examine how using tires that are at the current extremes of rolling resistance affects fuel consumption by light-duty vehicles in the U.S. The analysis was based on rolling-resistance measurements for 63 tire models that were obtained under uniform test conditions by Consumers Union (the publisher of Consumer Reports).
These tires represent a cross-section of the currently available T-, H-, and V-speed-rated tires for light-duty vehicles on the U.S. market. All 63 tire models were evaluated at the same load (1,033.9 lbs) and at the same inflation pressure (37.9 psi). The analysis was performed for each speed-rated subset of tires and for the combined set of all tires. The data are presented for the median,
minimum, and maximum of the respective distributions of rolling resistance, and for four
percentile levels (10th, 25th, 75th, and 90th).
Rolling resistance (RRf) for the combined set of all examined tires ranged from 6.89 lbs to
12.50 lbs, with a median of 10.28 lbs. Given that the current average on-road fuel economy of
light-duty vehicles is 21.4 MPG (assumed to be obtained at RRf of 10.28 lbs—the median of our
tire sample), the obtained rolling resistance extremes translate into a maximum fuel economy
of 22.4 mpg (at RRf = 6.89 lbs) and a minimum fuel economy of 20.7 MPG (at RRf = 12.50
lbs). Consequently, the obtained rolling resistance extremes yield a minimum and maximum
annual fuel consumption of 505 gallons and 547 gallons, respectively. At the average 2013
price of regular gasoline, the obtained fuel-consumption results in a $147 difference in the
annual cost of gasoline per light-duty vehicle.
In other words, over the course of a year, you may save the price of a tire by switching to an ‘eco’ tire (such as the Goodyear Assurance Fuel Max Radial Tire. If you are not hellbent on performance, low rolling resistance tires make a lot of sense.
Of course, if you want to go slideways and hoon like Clarkson, eco tires make a lot of sense too — the stiffer compound typically has less grip. Only road racers and drag racers need not apply.
So why not save some money during your vehicle’s tenure and go with a low rolling resistance tire to improve your economy next time you need rubber?