Will California Ban Some Tires?

• California wants to regulate tires to have lower rolling resistance.
• Tires that don’t meet the target won’t be eligible for sale in the state.
• This could ban track day tires from California.

California is at it again—new legislation is being explored by state policymakers in an attempt to regulate the tire industry. The California Energy Commission (CEC) wants to introduce a law that sets a minimum tire rolling resistance target to help save a claimed $1 billion in extra fuel costs experienced by drivers.

Basically, California is trying to set the performance standard for aftermarket tires, which can change almost everything, especially for enthusiasts who use inefficient but grippy high-performance tires. Here’s what we know.

What Is The Target?

In its report, the CEC outlined several performance metrics for tires, all of which centered around rolling resistance. It’s basically how it sounds: the less rolling resistance a tire has, the easier it is to roll, and the longer it can roll for a given amount of energy. Modern tire development focuses heavily on rolling resistance because it makes a sizeable impact on fuel economy and energy efficiency for EVs.

The CEC measures rolling resistance using ISO 28580:2018, resulting in a coefficient expressed in newtons per kilonewton (N/kN). It’s a bit mathy, but it’s basically the number of newtons, or force, required to overcome every 1,000 newtons of vehicle weight. More importantly, the CEC wants all tires to meet or exceed the standards of Original Equipment (OE) tires, which are the tires that come with the car when it’s brand new. Often, the OE tire is extremely efficient, but that comes with caveats we’ll explain later.

The proposal outlines an efficiency rating system as well, with the maximum rolling resistance set to 10.5 N/kN, with the most efficient tires landing around 6 N/kN. For reference, the Michelin Pilot Sport 4S, a popular 300-treadwear ultra-high-performance summer tire, lands at about 9.8 N/kN according to a few sources. Your average track day tire, like a Bridgestone Potenza RE-71RZ, Yokohama A052, or Maxxis VR2, will land in the middle teens, which is beyond the standard set by California.

Photo by: Honda

Does That Mean Fun Tires Are Dead?

As it stands, the legislation is clear: Tires that don’t meet the performance standard won’t be eligible for sale in California. There will be exemptions for tire models that sell fewer than 15,000 units a year, are ultra-high-treadwear (1,000 UTQG and above), are motorcycle tires, snow tires, and space-saver spares. That 15,000 number may be the saving grace of track day tires, though some models may outsell that number. Either way, it’s not looking great for ultra-grippy tires, though they represent such a tiny fraction of a bigger market that it shouldn’t be an issue for the average consumer.

But for the average enthusiast, most summer tires should land within California’s proposed rules, even if they’ll be considered inefficient. And these rules are only proposed, meaning they can be changed or even thrown out entirely. These rules are designed specifically for the commuting masses to protect average people from losing fuel efficiency over the lifetime of their vehicles. And of course, California wants to reduce overall emissions from tire particulates.

Photo by: Chris Rosales / Motor1

But Why?

California’s mission is noble, as there are no Federal standards for rolling resistance, though it may catch enthusiasts in the crossfire. There is also doubt that the standards will help the average person, as low rolling resistance tires in Europe often last half as long as American retail tires.

According to Tyre Reviews, the average European tire will last 27,000 miles compared to the 60,000 miles an American tire will see. That means double the tire consumption and double the production, which is a filthy manufacturing process that harms the environment and a greater cost for the consumer.

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At any rate, the proposed rules wouldn’t go into effect until January 1st, 2028. Until then, it will be argued and adjusted until it either passes or fails.

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Motor1’s Take: Don’t sound the alarm just yet, but the CEC’s rules would spell the end of track day tire sales in the US. Hopefully, the rules get adjusted so enthusiasts can still have their little slice of heaven.

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