Low-Rolling-Resistance Tires Can Save You Money at the Pump
Choosing the right tire can improve grip and reduce fuel consumption
Shoppers must consider many factors when buying tires: braking performance, wet-weather grip, how long they last, and price. But taking into account a tireās rolling resistance could save you money at the pump.
Exactly how much depends on your car and other factors, but CR tests show that itās possible to save a couple hundred dollars over the service life of a set of tires by choosing a model with low rolling resistance.
Rolling resistance refers to the energy it takes to rotate the tires, affected by the friction caused when the tire surface meets the road. The Department of Energy estimates that 4 to 11 percent of fuel consumption is due to tire rolling resistance.
There have been significant strides in tire technology designed to improve fuel economy, driven in part by automakers trying to meet increasingly stringent fuel-economy standards. Consumers also are eager to save at the pump, especially now.
Industry studies show that a 10 percent drop in rolling resistance equates to about a 1 percent improvement in fuel economy. It might not seem like a big difference, but fuel-economy gains are hard to come by. You can grab that advantage by making an informed tire purchase.
Performance All-Season-Tire Rolling Resistance
This bar graph ranks tested tires based on the rolling resistance we measured, and it illustrates how that resistance translates to fuel economy.
How Wear Affects Tire Performance
Tires provide the most traction when they are new, thanks to their deep and well-defined treads. With new tires, the rubber grips the dry road tenaciously, water is routed through the side grooves to resist hydroplaning, and they claw through snow. But thatās also when rolling resistance is at its worst.
This may surprise drivers who replace their worn-out tires for models known to provide excellent rolling resistance. The new tiresā fuel economy may not be as good as the old tiresā, but it will improve as the tires wear, Petersen says.
Of course, once your tire has reached 4ā32 inch, itās time to start looking for new tires, regardless of how good your fuel economy has become. And at 2ā32 inch, itās absolutely time to replace the tire.
We test hydroplaning resistance, wet braking, and snow traction at our Auto Test Center in Connecticut. Hydroplaning and wet braking evaluations are conducted on a portion of the track with a controlled water depth.
For hydroplaning, we measure the speed at which the tires skim on the water surface, signaling a loss of steering control. Wet braking is conducted from 60 mph and simply records the stopping distance. Snow traction is a measure of the distance traveled while accelerating from 5 to 20 mph on moderately packed snow. A tire that requires shorter distance to attain that speed has better snow traction.
If saving money is your primary goal when youāre shopping for your next set of tires, look beyond the purchase price to consider the long-term costs, reflected in both tread life and rolling resistance. Shoppers might naturally avoid expensive tires, but CRās tests routinely show that some of the priciest tires deliver both excellent traction and long life, making their true cost of ownership among the lowest.
How to Test Your Tire's Tread Depth
Grab a quarter and a penny to measure tread depth. Place the quarter upside down in a tire groove with a treadwear indicatorāraised bars within some grooves. They will appear flush with the tread when the tire is worn out. The distance from the quarterās edge to George Washingtonās hairline is about 4ā32 inch. If you can see all of Washingtonās head exposed, itās time to start shopping for new tiresāyou at least still have some grip left.
If there is some space exposed above Georgeās head, check the tire with a penny. Using the same technique, insert that penny into the same groove, and point Lincolnās head down. If you can see the top of Abeās head over the tread, the tire should be replaced immediately. Many states have made it illegal to use tires with a tread that shallow.
Photo: John Powers/Consumer Reports Photo: John Powers/Consumer Reports