California is the first US state to set efficiency standards for replacement tires, with the new rules designed to cut fuel and energy use without forcing drivers to swap out the tires they already have.
The California Energy Commission approved its Replacement Tire Efficiency Program on August 17, with the first standards taking effect in 2029. They apply to replacement tires sold for passenger vehicles and light-duty trucks, setting limits on rolling resistance alongside minimum wet-grip requirements.
Rolling resistance is basically the energy a tire needs to keep moving. Reducing it can improve fuel economy in petrol cars and help EVs travel farther on a charge. According to CEC, replacement tires are currently less efficient on average than those fitted to new vehicles.
Drivers should barely notice the cost during the first phase, which runs from 2029 to 2033. The CEC estimates compliant tires will cost around $1.50 more each, or $6 for a set of four, with a typical petrol car saving roughly $85 in fuel over a four-year tire life.
From 2033, the standards become stricter. The estimated extra cost rises to $6.50 per tire, or $26 for a full set, but projected fuel savings increase to about $179 over the same period.
Plenty of specialist tires are excluded, so the rules will not cover everything sitting on a tire-shop rack. Among the exceptions are Competition tires, winter tires, used and retreaded tires, certain off-road tires, motorcycle tires and temporary spares.
Once fully implemented, the CEC estimates the programme could save California drivers nearly $1 billion a year in petrol and electricity costs. It also expects annual CO2 emissions to fall by around two million metric tonnes.
The rulemaking has drawn plenty of industry input, with manufacturers and trade groups submitting comments throughout the process. Michelin has publicly backed the efficiency goals and said the thresholds are technically achievable within the proposed timeframes.
For California drivers, there is no immediate action required. The rules apply when new replacement tires are sold, so the change should happen gradually as less-efficient options disappear from the Californian market.