California sets first-ever replacement tire efficiency rules, aiming to slash fuel costs and emissions

California has become the first US state to adopt efficiency standards for replacement tires, a move expected to save drivers $1 billion (€860 million) annually in fuel and electricity costs while cutting CO2 emissions by 2 million tonnes. The California Energy Commission (CEC) unanimously approved the Replacement Tire Efficiency Program (RTEP) on 17 August 2026, with the first phase kicking off in 2029 and full implementation by 2033. The programme targets replacement tires for passenger vehicles and light-duty trucks sold in California. Under Phase 1 (2029–2033), base passenger car tires must meet a maximum rolling-resistance coefficient of 9.0, measured per ISO 28580:2018. This threshold tightens to 7.1 in Phase 2. Other tire categories—including light truck, low-load-index, long-life, ultra-long-life, and ultra-high-performance tires—face tailored efficiency requirements. All regulated tires must also meet a minimum wet-grip value of 1.0, tested under ISO 23671:2021. The CEC stated the standards ensure replacement tires are “at least as energy efficient, on average, as tires sold on new vehicles,” addressing a gap where average replacement tires are typically less efficient than original equipment tires. CEC chair David Hochschild highlighted that the programme will help Californians save nearly $1 billion per year on refuelling while reducing CO2 emissions by 2 million tonnes annually—equivalent to removing 400,000 petrol cars from the road. The incremental cost to consumers is projected at $1.50 per tire during Phase 1 and $6.50 per tire in Phase 2. A typical petrol car driver using compliant tires could save $179 in fuel over a set’s lifespan, based on gasoline prices of $4.60 per gallon. At mid-2026 gasoline prices, savings could rise by 25%. The CEC noted that compliant replacement tires are already available on the market. Michelin North America endorsed the efficiency goals, stating the proposed thresholds are technically achievable. “California’s direction is consistent with Michelin’s all-sustainable and holistic approach for reducing the impact of tires at every stage of the life cycle,” said Francesca Mosteller, director of state & local government affairs at Michelin North America. The CEC conducted extensive laboratory testing of California’s most popular replacement tires and reviewed industry data from companies like Discount Tire, confirming the regulation is cost-effective and feasible with no trade-offs for tire lifespan, safety, or other characteristics. The commission also engaged with stakeholders over five years, creating exemptions for specialty tires such as sports tires, large off-road tires, and all-weather winter performance tires. Additional product categories were established for long-life, ultra-high-performance, low-load-index, and other specialty tires. The CEC pledged to continue collaborating with stakeholders to ensure equitable and effective enforcement as the programme rolls out.