Study finds 6.3% spread in fuel economy obtained with maximum and minimum rolling resistance tires
08 January 2016
A new report by University of Michigan Transportation Research Institute (UMTRI) researcher Dr. Michael Sivak has found a 6.3% spread between the fuel economy obtained with maximum and minimum rolling resistance tires. At the average 2015 price of regular gasoline, the obtained fuel-consumption extremes result in a $78 difference in the annual cost of gasoline per light-duty vehicle, Sivak said.
The US Transportation Research Board estimates that a 10% increase in tire rolling resistance will result in about a 1-2% decrease in the fuel economy of light-duty vehicles.
Updating research from 2014, Sivak examined the rolling-resistance measurements for 49 new same-sized tire models obtained from Consumers Union at the same load and inflation pressure to calculate the fuel consumed annually by an average driver. He then calculated differences in fuel used (and money spent) between tires at the extremes of rolling resistance.
The tires represented a cross-section of the currently available T-, H- and V-speed-rated tires for light-duty vehicles on the U.S. market (maximum speeds for each of these types of speed-rated tires are 118 mph, 130 mph and 149 mph, respectively).
Rolling resistance (RRf) for the combined set of all tires examined ranged from 8.1 lbs. to 12.1 lbs., with a median of 10.28 lbs. For the average vehicle currently on the road, the rolling resistance extremes translate into a maximum fuel economy of 22.2 mpg (RRf at 8.1 lbs.) and a minimum of 20.9 mpg (RRf of 12.1 lbs.), with an average of 21.6 mpg (RRf at 9.9 lbs.).
For the combined set of all tires, the added fuel consumed with tires at the current maximum rolling resistance represents a 6.3 percent increase compared to the fuel consumed with tires at the current minimum rolling resistance.
Resources
Michael Sivak (2016) “Benefits of Using Tires with Low Rolling Resistance” UMTRI-2016-1
Why would anybody use maximum rolling resistance tires?
Posted by: HarveyD | 08 January 2016 at 10:29 AM
Traction.
Posted by: Engineer-Poet | 08 January 2016 at 11:41 AM
We have to use (by law) winter tires for added traction between 15 Dec and 15 March.
Posted by: HarveyD | 08 January 2016 at 01:33 PM
A $78 yearly saving at these low gas prices is good, unless, these tires would be much more expensive that the comparative tires. Higher efficiency would suggest a quieter tire, but what about other attributes like gripping capability.
Posted by: NorthernPiker | 08 January 2016 at 02:47 PM
This study should not be subsidized by tax payers, i hope. Just put more psi in your tires and you will have lower resistance tires and better fuel economy. I always choose the cheapest brand of tires, put some excessive psi and drive slow except in my motorcycle where i always put bridgestone at correct psi.
Posted by: gorr | 08 January 2016 at 07:21 PM
HarveyD, you just need the right winter Tire and then you can have the best of both worlds - excellent snow traction and low rolling resistance. Check out the Nokian Hakkapeliitta R2, for example.
There really ought to be a standardized test run on tires to rate rolling resistance, and it should be mandatory.
Posted by: Dave R | 09 January 2016 at 08:42 AM
@Dave R...you are correct. The market offers excellent low rolling resistance winter and summer tires. Nokian and Michelin are excellent suppliers of both. That's what we use on our Toyota HEVs.
Nokian (more costly) sells a rare 4-season tire legally accepted in our area. Others will probably follow soon.
Posted by: HarveyD | 09 January 2016 at 03:55 PM