This popped up today https://www.theguardian.com/us-news/2026/aug/19/california-replacement-tires, restrictions on what tyres can be bought based on their 'energy efficiency'.

In my mind energy efficiency is ok for the environment but pretty poor when it comes to tyres that stay attached to the road. I don't mind certain products being advised or promoted, but mandated is a different thing.

Hmmm ya see I have a professional interest in all this kind of stuff.

The Californians are tackling one of the largest mechanical losses of a modern car - 'rolling resistance' of the tyres.

The European Union has taken a slightly different tack and has mandated a limit to tyre wear emmisions via the latest Euro7 emmision requirements.

The Californian requirement is tackling the same issue via a different route.

Tyre wear and Rolling resistance are effectively the same issue. Tackle one and you also reduce the other.

I think reducing tyre wear while improving overall efficiency, whether that's miles per gallon or electric vehicle range, is a good thing.