On Monday, the state of California confirmed that it is officially proceeding with its Replacement Tyre Efficiency Programme. Run by the California Energy Commission, this will become the first set of regulations in the United States governing which replacement tyres can be sold in the aftermarket.

We have covered the Replacement Tyre Efficiency Programme extensively in the months ahead of its approval. The rules first put forward were revised following a public comment period, and those changes proved important because they created room for a wider range of specialist tyres to remain on sale. Of particular interest to enthusiasts, the updated framework included exemptions for high-performance competition tyres, while other carve-outs also cover off-road tyres, all-season winter performance tyres, and other examples previously detailed.

The programme drew both support and opposition during the public comment process. Tyre makers such as Michelin and Bridgestone backed the programme, while also emphasising the importance of maintaining the right balance between safety and efficiency gains. Fellow tyre manufacturer Dunlop issued a restrained response after the programme was approved, stating, “California should evaluate the complete consequences of replacement tyre requirements,” and urging the state to keep working with tyre manufacturers, consumers, and the auto industry to deliver environmental progress “without creating material adverse impacts on consumers, consumer choice, competition, or trade.”

Remaining opposed until the final stage, however, was the Specialty Equipment Market Association, better known as SEMA. Pointing to “unresolved concerns about tyre affordability, consumer choice and the impact on small businesses,” SEMA said it continues to oppose the regulation. Even so, the organisation also acknowledged that the final proposal “is significantly improved from where the rulemaking began.”

The new standards were approved unanimously by CEC commissioners, and regulators believe that, once implemented, they will collectively save California drivers nearly $1 billion and cut CO2 emissions by 2 million metric tons per year. The first phase of the regulations is scheduled to begin in 2029, with a tougher set of rules due to take effect from 2033 onward.