SACRAMENTO, Calif., Aug. 19 (Our California Times) — California drivers will face new limits on some replacement tires beginning in 2029, after the California Energy Commission unanimously approved standards for how much energy tires may use as they roll along the road.
The rules are planned in two stages. The first begins in 2029, when covered replacement tires will be limited to a maximum rolling-resistance level of 9.1 newtons per kilonewton, or N/kN. The limit falls to 7.2 N/kN in 2033.
The change was adopted by the state energy commission under authority from Assembly Bill 844, a 2003 law that directed the commission to pursue tire-efficiency standards. The rules have been approved, but the restrictions will not begin until 2029.
What the rules cover
The standards apply to covered replacement tires offered for sale in California. They do not apply to tires originally installed on new vehicles, according to the California Energy Commission’s explanation of the rules.
Rolling resistance is the force that tires must overcome to keep moving on pavement. Tires with lower rolling resistance generally require less energy to move, which can reduce gasoline use in vehicles with engines and electricity use in electric vehicles.
The commission says the goal is to ensure that replacement tires are, on average, at least as energy-efficient as the original-equipment tires supplied with passenger cars and light-duty trucks.
The commission tested 537 types of tires while developing the standards. It also included wet-grip requirements intended to preserve traction and safety, although the available summaries do not specify the wet-grip thresholds.
Which tires are exempt?
The rules do not cover every type of tire. Exemptions described by the commission include competition tires; winter and some winter-performance all-season tires; used and retreaded tires; deep-tread tires; certain off-road and all-terrain-vehicle tires; motorcycle tires; temporary-use and space-saver spare tires; and small tires with nominal rim diameters of 13 inches or less.
Other listed exemptions include limited-production tires, emergency-vehicle tires, high-load-index tires and tires that cannot sustain speeds above 50 mph.
That means the effect will depend on the type of vehicle and tire being replaced. A driver seeking a standard replacement tire for a passenger car or light-duty truck is more likely to encounter the new limits than someone buying one of the exempt categories.
What could change for drivers?
The California Energy Commission estimates that the standards could lower energy costs for vehicle owners. Its projection is $79 in savings over four months under the first phase and about $153 over seven months under the stricter second phase.
Those figures are agency estimates, not guaranteed savings for every driver. Actual results would depend on factors such as the vehicle, driving conditions, tire pressure and fuel or electricity prices.
The commission and public statements cited in coverage also indicate that the available selection could shrink significantly by 2033. Reports have put the possible reduction at about 70% of tires now sold in California, but the research available for this article does not establish a single official source or methodology for that estimate.
The supplied public information also does not establish how tire prices may change, how retailers will be required to comply or how the state will enforce the standards. Those details will matter to drivers, tire shops and manufacturers as the 2029 start date approaches.
Why the state adopted the standards
The commission’s position is that replacement tires should not be less energy-efficient than the tires installed on a new vehicle. The rules are intended to reduce the energy needed to move vehicles while maintaining safety through wet-grip requirements and exemptions for specialized tires.
For drivers, the practical change is not an immediate requirement to replace existing tires. The rules concern the future sale of covered replacement tires. California vehicle owners can continue using tires already on their vehicles, subject to ordinary safety and maintenance requirements.
The next major date is 2029, when the first rolling-resistance limit is scheduled to take effect. The stricter 7.2 N/kN threshold is scheduled for 2033.
