New California Tire Law – What's It All About?

If you've been anywhere near automotive social media in the last few weeks, you might have seen some version of the same headline: California has banned 70% of tires. What followed was the usual: outrage posts and at least a few people asking whether they need to stockpile rubber before the state comes for their current set. While this is a real regulation with real-life consequences, almost none of them are what the headlines described.

Nobody's tires will suddenly become illegal. Nothing changes this year, next year, or the year after that. And the single number driving the entire panic turns out to have a much more specific origin than "70% of tires." That said, dismissing it entirely would be the opposite mistake, which is why in this article we're going to take a closer look at the Replacement Tire Efficiency Program and what it actually means to California drivers. If you're interested in more than just the latest automotive premieres, then this is something you're going to want to read.

Replacement Tire Efficiency Program – What Actually Changes?

The California Energy Commission adopted the Replacement Tire Efficiency Program on August 17, 2026. It's the first set of replacement tire efficiency standards for passenger vehicle and light-duty trucks tires anywhere in the United States.

However, while it is the first of its kind, the underlying logic isn't new and it isn't even from this decade. Assembly Bill 844, passed back in 2003, directed the Commission to establish a program ensuring replacement tires sold in California are at least as energy-efficient as the tires fitted to new vehicles as original equipment.

This makes more sense and ties in with the fact that the tires installed in new cars are generally designed for better fuel mileage or electric range. At the same time, average replacement tires are often less efficient – meaning drivers often lose mileage and range the moment they replace them. Nowadays the latter is especially noticeable with the EVs, which are highly sensitive to even the most minor changes in wheel and tire combos.

The underlying mechanism is rolling resistance or, in simpler terms, how much energy your tires waste as they turn. The regulation caps it measured as a rolling resistance coefficient, with a separate wet grip floor to stop manufacturers from simply trading away safety to hit the better efficiency number.

Where the 70% Figure Came From

This is the part worth slowing down for, because one number generated all of the panic.

The figure came from the Commission's June public hearing, where a representative of the Discount Tire chain of tire stores (also known as America's Tire) voiced their doubts regarding the legislation. They told the Commission that if the then-proposed Phase 2 requirements were applied to the tires they sell in California (as of then), roughly 70 percent of currently available options would come off the market.

While that does seem like a lot, we need to remember two things:

1. It's just one retailer's range, not the entire market
2. It was measured against the April proposal, before a substantial package of exemptions was added in July.

Anyway, let's see what "efficient tires" actually mean according to the legislation.

The Replacement Tire Efficiency Standards Exemptions

The final text doesn't set one limit. It sets six, plus a wet grip standard, plus several routes out of the rule entirely. Below is a little cheat-sheet table listing the different coefficients for each tire category. Note that lower numbers are stricter. Where a tire qualifies under multiple categories, the most lenient ceiling applies.

The bottom row is the one that matters most and got essentially zero coverage. Any tire carrying the three-peak mountain snowflake symbol comes out of the performance limits entirely – and out of the wet grip requirement too.

There are two separate routes, and together they divide the 3PMSF market cleanly. Passenger-metric snowflake tires become "all-season winter performance" tires and are exempt from the standards. Light-truck snowflake tires get classified as winter-type snow tires and are struck from the definition of a replacement tire altogether, meaning the regulation simply doesn't reach them.

Competition tires are excluded as well, provided they meet four criteria simultaneously: tread depth of 8/32″ or less, a W/Y speed rating, UTQG treadwear of 200 or below, and not classified as all-season.

Where the Criticism Actually Lands – The Cost

The Commission's position is that this saves money.

Their estimate: nearly $1 billion per year in gasoline and electricity costs statewide, plus a 2 million metric ton annual reduction in carbon dioxide emissions. Which is an equivalent to removing 400,000 gasoline cars from California roads altogether. Per driver, they put it at roughly $180 in fuel savings over the lifetime of a set.

These are just government estimates though, and the coalition of tire companies wrote to the Commission arguing that tires capable of meeting Phase 2 rolling resistance typically cost hundreds of dollars more per set than baseline alternatives, and that with realistic pricing applied, projected fuel savings wouldn't offset the higher upfront cost.

The UHP or Competition Tires Trap

This one's genuinely odd, and enthusiasts should know about it.

Ultra-high-performance tires get the most generous offset in the regulation – 8.5 rather than 7.1 in Phase 2. But qualifying as UHP requires a W, Y, or (Y) speed symbol, capability of 168 mph or more, and a relative wet grip index of at least 1.45.

Miss 1.45 and the tire isn't UHP under the rule at all. It drops to the base standard – 7.1, the strictest number in the regulation.

Summer UHP tires are generally well-positioned to clear that bar. The exposed segment is non-3PMSF UHP all-seasons: it trades wet grip away for cold-weather capability, doesn't carry the snowflake that would exempt it, and isn't optimised for rolling resistance either. Pirelli put the objection on the record, arguing the wet grip requirement is too demanding for tires designed around dry performance. The Commission left it unchanged – staff described the design as deliberate, structuring things so better wet grip earns compliance headroom.

Why Any of It Actually Matters?

The specific panic was overblown, so there is that.

However, the underlying trend – regulations quietly reshaping what you can buy for your car, and what it costs – is completely real, and this is one small piece of it. Think about what's already happened in the last decade. Emissions standards pushed manufacturers toward turbocharged downsizing, then toward hybridisation, then toward electrification timelines.

Sustainable production requirements changed what materials go into interiors and even exteriors, as illustrated by BMW's flax-based carbon fiber replacement. Each of those shifted pricing, not just on cars, but on the parts and accessories built around them, yet none of it arrived as a single dramatic headline. It sneaked past our attention, buried under pages of legislation.

California matters disproportionately here because of its size. It's the largest car market in the country, which historically means manufacturers often build to California's rules and then sell it everywhere else, because it's cheaper to maintain less product versions. Whether that happens with tires depends entirely on how manufacturers respond, but the mere possibility is why "it only applies in California" shouldn't fully settle the question for drivers elsewhere.

The Short Answer – Don't Panic!

So no, don't panic. Your tires are fine. Your next set is fine. The set after that is probably fine too.

But do pay attention, and specifically to the boring parts. The California tire law is real, it's the first of its kind in the US, and it will eventually change which replacement tires can be sold in the state. That being said, it also doesn't ban a single tire you currently own, doesn't take effect until 2029 at the earliest, still has an administrative review step to clear, and contains enough exemptions that the viral "70%" figure bears little resemblance to the final text.

Our advice is the same as it would be for any regulatory change affecting what you can buy for your car – don't panic-buy, don't rage-post (spreading the misinformation), and do keep half an eye on what's coming. The rules governing personal transportation are moving faster than they used to, and understanding them early is cheaper than finding out late.