California Replacement Tire Restrictions: New Rules Approved by Regulators

March 17, 2025 – California regulators voted today to approve a sweeping set of new restrictions on replacement tires, marking the most significant state-level shift in tire standards in over a decade. The California Air Resources Board (CARB) passed the measure in a 9–2 vote, aiming to reduce rolling resistance, improve wet traction, and standardize labeling for all passenger replacement tires sold in the state.

The new rules, which will take effect on January 1, 2026, require all replacement tires to meet minimum performance thresholds for tread wear, fuel efficiency, and safety. Key provisions include:

• Minimum tread depth at replacement: Tires must be replaced when tread depth reaches 2/32 of an inch, aligning with existing safety recommendations but now codified as a legal requirement.
• Rolling resistance grades: All tires must display a rolling resistance grade on the sidewall, similar to the current UTQG system, to help consumers choose fuel-efficient options.
• Wet braking performance: A standardized wet braking index will be required, with a minimum score of 60 (on a 100-point scale) to pass.

“This is about giving drivers the information they need to make safer, more economical choices,” said CARB board member Dr. Elena Torres. “Replacement tires are often overlooked, yet they can account for up to 10% of a vehicle’s fuel consumption.”

The move follows years of research by the California Energy Commission, which found that poorly maintained or low-quality replacement tires cost state drivers an estimated $1.2 billion annually in extra fuel costs. The new restrictions are expected to reduce greenhouse gas emissions by 2.3 million metric tons per year by 2030.

Industry reaction has been mixed. The Tire Industry Association (TIA) expressed concern over compliance costs, estimating that smaller retailers may need to invest up to $50,000 for new testing equipment and labeling systems. However, major manufacturers like Michelin and Bridgestone have already begun producing tires that meet the new standards, calling the regulation “a logical evolution.”

Consumer advocates welcomed the move. “For too long, drivers have been left to guess which replacement tires are safe and efficient,” said Mark Jansen, policy director at the Center for Auto Safety. “These rules put California at the forefront of tire transparency.”

The restrictions apply only to replacement tires for passenger cars, light trucks, and SUVs. Original equipment tires on new vehicles remain exempt. Enforcement will be handled through random inspections at retailers and distribution centers, with fines of up to $10,000 per violation for non-compliance.

Car owners should note that the new tread depth requirement does not change recommended seasonal tire practices. Winter tires, for example, still need deeper tread for snow traction. The CARB rule also includes a grace period for tires manufactured before 2026, which can be sold through the end of 2027.

To prepare, drivers should check their current tire’s DOT code and tread depth. The agency will launch a public awareness campaign this summer, including an online tool to compare tire grades.

As the first state to mandate such comprehensive replacement tire restrictions, California is likely to influence federal policy. The National Highway Traffic Safety Administration (NHTSA) is reportedly reviewing similar guidelines, though no formal proposal has been made.