Low-rolling resistance tires
Encyclopedia
Low-rolling resistance
tires minimize wasted energy as a tire rolls, thereby decreasing required rolling effort — and in the case of automotive applications, improving vehicle fuel efficiency
. Approximately 5–15% of the fuel consumed by a typical car may be used to overcome rolling resistance. A 2003 California Energy Commission
(CEC) preliminary study estimated that adoption of low-rolling resistance tires could save 1.5–4.5% of all gasoline consumption, but that current data were also insufficient to compare safety and other characteristics. A database of much more complete data will be released by the CEC pending completion of an ongoing study.
and SAE J2452
) are usually performed on new tires.
When measured by using these standard test practices, most new passenger tires have reported RRCs ranging from 0.007 to 0.014. In the case of bicycle tires, values of 0.0025 to 0.005 are achieved. These coefficients are measured on rollers, with power meters on road surfaces, or with coast-down tests. In the latter two cases, the effect of air resistance must be subtracted or the tests performed at very low speeds.
In 2009 The CEC used a rating called Rolling Resistance Force RRF. RRF and RRC, rolling resistance coefficient are very similar. Difference is taking the RRF and dividing it by the load(weight) to get RRC. So a Michelin Harmony tire rated at 9.45 RRF at 1000 pounds load would be .0095 RRC.
In Canada
, Transport Canada
tests will be conducted on a number of different tires mounted on 15 and 16-inch rims – the most common tire sizes in Canada – to determine how rolling resistance is influenced by vehicle size, tire width and profile. Results will be used to inform Canadians about the types of low rolling resistance tires available in Canada, and whether they can help reduce fuel consumption and pollutants from passenger vehicles.
Auto manufacturers in the United States
typically equip new vehicles with tires that have lower rolling resistance than their average after-market replacements, in order to meet Corporate Average Fuel Economy
(CAFE) standards.
These include Conti Contact, Michelin Energy, and Goodyear Eagle LS tires.
Transportation Research Board
Special Report 286 and the March 2003 Green Seal
report on the topic.
Here is a list of Consumer Report's tires that achieved their best rolling resistance rating. The tires at the top of the list are rated higher overall.
Below are the light duty tires (as reported by Consumer reports) achieving their best rolling resistance rating. Again, higher overall rated tires are closer to the top of the list.
Followed by:
New models by 2009:
A Union of Concerned Scientists
newsletter says "LRR tires also meet the same federal standards for treadwear, traction, and temperature resistance as regular tires."
Older Low-rolling resistance tires may reduce ability to grip, especially when taking corners, and may also wear out more rapidly.
has new rolling resistance requirements that went into effect in July 2008. The law was passed in 2003 and the standards and reporting requirements were finalized in 2007.
eco-label
Rolling resistance
Rolling resistance, sometimes called rolling friction or rolling drag, is the resistance that occurs when a round object such as a ball or tire rolls on a flat surface, in steady velocity straight line motion. It is caused mainly by the deformation of the object, the deformation of the surface, or...
tires minimize wasted energy as a tire rolls, thereby decreasing required rolling effort — and in the case of automotive applications, improving vehicle fuel efficiency
Fuel efficiency
Fuel efficiency is a form of thermal efficiency, meaning the efficiency of a process that converts chemical potential energy contained in a carrier fuel into kinetic energy or work. Overall fuel efficiency may vary per device, which in turn may vary per application, and this spectrum of variance is...
. Approximately 5–15% of the fuel consumed by a typical car may be used to overcome rolling resistance. A 2003 California Energy Commission
California Energy Commission
The California Energy Commission is California’s primary energy policy and planning agency. Created in 1974 and headquartered in Sacramento, the Commission has responsibility for activities that include forecasting future energy needs, promoting energy efficiency through appliance and building...
(CEC) preliminary study estimated that adoption of low-rolling resistance tires could save 1.5–4.5% of all gasoline consumption, but that current data were also insufficient to compare safety and other characteristics. A database of much more complete data will be released by the CEC pending completion of an ongoing study.
Measuring rolling resistance in tires
Rolling resistance can be expressed with the rolling resistance coefficient (RRC), which is the value of the rolling resistance force divided by the wheel load. A lower coefficient means the tires will use less energy to travel a certain distance. The coefficient is mostly considered as independent of speed, but for precise calculations it is tabled at several speeds or an additional speed-dependent part is used. The Society of Automotive Engineers (SAE) has developed test practices to measure the RRC of tires. These tests (SAE J1269SAE J1269
SAE J1269 is a standard test defined by the Society of Automotive Engineers to measure the rolling resistance of tires.The rolling resistance coefficient thus measured indicates the proportion of energy that is lost to the hysteresis of the material as the tire rolls....
and SAE J2452
SAE J2452
SAE J2452 is a standard defined by the Society of Automotive Engineers to define the rolling resistance of tires.The rolling resistance coefficient indicates the amount of force required to overcome the hysteresis of the material as the tire rolls...
) are usually performed on new tires.
When measured by using these standard test practices, most new passenger tires have reported RRCs ranging from 0.007 to 0.014. In the case of bicycle tires, values of 0.0025 to 0.005 are achieved. These coefficients are measured on rollers, with power meters on road surfaces, or with coast-down tests. In the latter two cases, the effect of air resistance must be subtracted or the tests performed at very low speeds.
In 2009 The CEC used a rating called Rolling Resistance Force RRF. RRF and RRC, rolling resistance coefficient are very similar. Difference is taking the RRF and dividing it by the load(weight) to get RRC. So a Michelin Harmony tire rated at 9.45 RRF at 1000 pounds load would be .0095 RRC.
In Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
, Transport Canada
Transport Canada
Transport Canada is the department within the government of Canada which is responsible for developing regulations, policies and services of transportation in Canada. It is part of the Transportation, Infrastructure and Communities portfolio...
tests will be conducted on a number of different tires mounted on 15 and 16-inch rims – the most common tire sizes in Canada – to determine how rolling resistance is influenced by vehicle size, tire width and profile. Results will be used to inform Canadians about the types of low rolling resistance tires available in Canada, and whether they can help reduce fuel consumption and pollutants from passenger vehicles.
Standard equipment
Most hybrid vehicles are equipped with low-rolling resistance tires.Auto manufacturers in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
typically equip new vehicles with tires that have lower rolling resistance than their average after-market replacements, in order to meet Corporate Average Fuel Economy
Corporate Average Fuel Economy
The Corporate Average Fuel Economy are regulations in the United States, first enacted by the U.S. Congress in 1975, and intended to improve the average fuel economy of cars and light trucks sold in the US in the wake of the 1973 Arab Oil Embargo...
(CAFE) standards.
These include Conti Contact, Michelin Energy, and Goodyear Eagle LS tires.
Available tires
Some tires available in 2003 ranked by coefficient from lowest (least wasteful), according to the United States National Academy of SciencesUnited States National Academy of Sciences
The National Academy of Sciences is a corporation in the United States whose members serve pro bono as "advisers to the nation on science, engineering, and medicine." As a national academy, new members of the organization are elected annually by current members, based on their distinguished and...
Transportation Research Board
Transportation Research Board
The Transportation Research Board is a division of the National Research Council, which serves as an independent adviser to the President, the Congress and federal agencies on scientific and technical questions of national importance...
Special Report 286 and the March 2003 Green Seal
Green Seal
Green Seal is a non-profit, third-party certifier and standards development body in the United States. Since 1989 it has provided independent, objective, science-based guidance to the marketplace and to consumers...
report on the topic.
- 0.00615 BridgestoneBridgestoneThe is a multinational rubber conglomerate founded in 1931 by in the city of Kurume, Fukuoka, Japan. The name Bridgestone comes from a calque translation and transposition of ishibashi, meaning "stone bridge" in Japanese....
B381 P185/70R14 - 0.00650 MichelinMichelinMichelin is a tyre manufacturer based in Clermont-Ferrand in the Auvergne région of France. It is one of the two largest tyre manufacturers in the world along with Bridgestone. In addition to the Michelin brand, it also owns the BFGoodrich, Kleber, Riken, Kormoran and Uniroyal tyre brands...
SYMMETRY P225/60R16 - 0.00683 Michelin TIGER PAW AWP P225/60R16
- 0.00700 Bridgestone DUELER H/T 113S P265/70R17
- 0.00709 BFGoodrichBFGoodrichBFGoodrich is an American brand of tires. Separated from the Goodrich company and now owned by Michelin.Some Michelin competition tyres are now branded BFGoodrich to increase brand awareness....
RUGGED TRAIL T/A P285/70R17 - 0.00754 Michelin LTX A/S P255/65R17
- 0.00758 GoodyearGoodyear Tire and Rubber CompanyThe Goodyear Tire & Rubber Company was founded in 1898 by Frank Seiberling. Goodyear manufactures tires for automobiles, commercial trucks, light trucks, SUVs, race cars, airplanes, farm equipment and heavy earth-mover machinery....
INTEGRITY (OE) P225/60R16 - 0.00760 Bridgestone INSIGNIA SE 200 89S P195/65R15
- 0.00767 BFGoodrichBFGoodrichBFGoodrich is an American brand of tires. Separated from the Goodrich company and now owned by Michelin.Some Michelin competition tyres are now branded BFGoodrich to increase brand awareness....
RUGGED TRAIL T/A P245/65R17 - 0.00780 ContinentalContinental tireA Continental tire is an upright, external, mounted spare tire behind an automobile's trunk compartment. The term also describes a non-functional bulge that is stamped into the trunk lid or a cosmetic accessory to the rear of the car giving the impression of a spare tire mount.-Development:The...
Ameri-G4S WS P235/75R15 - 0.00783 Continental CrossContact LX
- 0.00795 Michelin TPAW TOURING TR/SR P215/70R16
- 0.00810 Bridgestone DUELER H/T 104S P235/70R16
- 0.00813 Goodyear Invicta GL 235/75R15
- 0.00825 Continental ContiTouring Contact CH95 P205/55R16
- 0.00829 Michelin CROSS TERRAIN SUV P255/75R17
- 0.00833 Michelin PILOT PRIMACY 275/50R19
- 0.00850 Michelin ENERGY LX4 P225/60R16
- 0.00854 Michelin PILOT LTX P265/70R17
- 0.00855 Michelin ENERGY MXV4 PLUS 235/65R17
Here is a list of Consumer Report's tires that achieved their best rolling resistance rating. The tires at the top of the list are rated higher overall.
- Highly rated:
- All Season
- Michelin X Radial
- Michelin Agility Touring
- Michelin Harmony
- Toyo 800 Ultra
- Sumitomo HTR T4
- Middle rank
- Performance All Season
- Michelin Energy MXV4 Plus
- Continental ContiPremierContact H
- Least benefit
- All Season Ultra High Performance
- General Exclaim UHP
- Continental ContiExtremeContact
Below are the light duty tires (as reported by Consumer reports) achieving their best rolling resistance rating. Again, higher overall rated tires are closer to the top of the list.
- All-season
- Bridgestone Dueler H/T D684
- Michelin Cross Terrain
- Continental ContiTrac SUV
- BFGoodrich Radial Long Trail T/A
Followed by:
- All-terrain
- Continental ContiTrac TR
New models by 2009:
- Michelin Energy Saver
- Goodyear Assurance Fuel Max
Comparison with conventional tires
Depending on the specific technique and materials used by the manufacturers, tire life may be as good as conventional tires, and traction may also be as good.A Union of Concerned Scientists
Union of Concerned Scientists
The Union of Concerned Scientists is a nonprofit science advocacy group based in the United States. The UCS membership includes many private citizens in addition to professional scientists. James J...
newsletter says "LRR tires also meet the same federal standards for treadwear, traction, and temperature resistance as regular tires."
Older Low-rolling resistance tires may reduce ability to grip, especially when taking corners, and may also wear out more rapidly.
Regional Requirements
CaliforniaCalifornia
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
has new rolling resistance requirements that went into effect in July 2008. The law was passed in 2003 and the standards and reporting requirements were finalized in 2007.
Certifications
Passenger tires are tested for rolling resistance in order to obtain the German Blue AngelBlue Angel (certification)
The Blue Angel is a German certification for products and services that have environmentally friendly aspects.It has been awarded since 1978 by the Jury Umweltzeichen, a group of 13 persons from environment and consumer protection groups, industry, unions, trade, media and churches.Blue Angel is...
eco-label
See also
- Low-energy vehicleLow-energy vehicleA Low-energy vehicle is any type of vehicle that uses less energy than a regular fossil fuel vehicle.Higher efficiency can be achieved by changing the vehicle's design, and/or by modifying its powertrain. Energy consumption as low as 5-12.5 kWh/100 km is achieved directly by battery electric...
- Rolling resistanceRolling resistanceRolling resistance, sometimes called rolling friction or rolling drag, is the resistance that occurs when a round object such as a ball or tire rolls on a flat surface, in steady velocity straight line motion. It is caused mainly by the deformation of the object, the deformation of the surface, or...
- Fuel efficiencyFuel efficiencyFuel efficiency is a form of thermal efficiency, meaning the efficiency of a process that converts chemical potential energy contained in a carrier fuel into kinetic energy or work. Overall fuel efficiency may vary per device, which in turn may vary per application, and this spectrum of variance is...
- Blue Angel (certification)Blue Angel (certification)The Blue Angel is a German certification for products and services that have environmentally friendly aspects.It has been awarded since 1978 by the Jury Umweltzeichen, a group of 13 persons from environment and consumer protection groups, industry, unions, trade, media and churches.Blue Angel is...