California's new tire efficiency rules could save drivers $1B a year

Post by frumper » Wed, Aug 19, 2026, 3:58 PM UTC

mikestorrent wrote: post #109

legitster wrote: post #71

There are basically three major trade-off when it comes to tire compounds: rolling resistance, traction, and tire wear. You can pick 2 of the 3. When you shop for tires, manufacturers will try to make this eminently clear in the marketing - you pay a premium for tires that maximize on one or two of these features. The changes that California is proposing basically means you are going to have to choose between tractio…

Only Californians could dream up a stupid program like this and pretend that it's environmentally protective to send a ton more tire particles into the ecosystem, while costing consumers more, and probably increasing their carbon footprint at the manufacturing level, just to get shitty tires that might make a car a tiny bit more efficient. I had a set of these low-rolling-resistance tires stock on an early FWD EV I h…

Post by Hugsbox » Wed, Aug 19, 2026, 4:27 PM UTC

dmitrygr wrote: post #94

burnt-resistor wrote: post #24

Typically, there's a trade-off between rolling resistance/energy efficiency and traction/low noise. It's very easy to make long-lasting, efficient tires that are unsafe. It's difficult to make them both categories and quiet. Maybe single occupancy personal vehicles are wasteful and mass transportation should be invested in rather than shaming individual into token behaviors compared to large-scale waste and consumpti…

> Maybe single occupancy personal vehicles are wasteful and mass transportation should be invested in rather than shaming individual no amount of shaming will make me not consider my family's safety. mass transit in CA (eg: https://www.opportunitynowsv.org/blog/nobody-feels-comfortab... ) is not safe due to lack of serious policing. my family is prohibited from taking mass transit in usa. It is ok in japan and singap…

Post by antonymoose » Wed, Aug 19, 2026, 5:40 PM UTC

mdasen wrote: post #114

legitster wrote: post #71

There are basically three major trade-off when it comes to tire compounds: rolling resistance, traction, and tire wear. You can pick 2 of the 3. When you shop for tires, manufacturers will try to make this eminently clear in the marketing - you pay a premium for tires that maximize on one or two of these features. The changes that California is proposing basically means you are going to have to choose between tractio…

Yes, there are trade-offs, but you can get really great tires on all three. The Michelin CrossClimate2 tires are arguably the best traction tires, Consumer Reports estimates 95,000 miles of tread life in their testing (higher than basically anything else), and they got a 4/5 for rolling resistance on Consumer Reports' dynamometer testing. There's a lot of tires that are poorly made and just bad tires. For example, on…

Post by lazide » Wed, Aug 19, 2026, 6:04 PM UTC

testing22321 wrote: post #256

lazide wrote: post #238

Earlier quoted context omitted.

Except there are clear health hazards likely to happen from this change, such as increased tire particulates, and the nominal improvement (co2) is such a diffuse hazard (with limited direct health consequences) that it is likely to get lost in the noise.

Every change to a complex situation will have negative outcomes. A study was done, and they have clear data to make this decision. As time moves forward, new studies can be done addressing your concerns, and decisions can be made about addressing those. Don’t let perfect be the enemy of the good.

Post by AngryData » Wed, Aug 19, 2026, 6:23 PM UTC

ragall wrote: post #213

Aurornis wrote: post #150

Earlier quoted context omitted.

It's even worse than that. Rain performance and rolling resistance are conflicting goals. A good rain tire will need more voids to channel the water, but adding a lot of voids increases rolling resistance. California is a large market. Tire manufacturers probably won't make many California-specific tires. They're going to try to adjust their tires to meet the California guidelines. The most populous areas of Californ…

Tire manufacturers tend to have different compounds for Europe (focused on lower rolling resistance) and North America (focused on traction and a wider range of working temperatures). I'd guess that California will now simply get the EU variants instead of the NA variants.