Update: On Feb 14, 2023, the California Energy Commission will present its proposal on tire rolling resistance:
https://lnks.gd/l/eyJhbGciOiJIUzI1Ni...153911824768-l
Highlights:
They are using the same scale as the European Union, except instead of using letters and colors, they are using stars.
They plan on having a database populated by the tire manufacturers which would include the RRC value (Rolling Resistance Coefficient), and Peak Friction from the UTQG traction test (Currently the UTQG rating is based on the sliding value), and the MSRP (Manufacturers Suggested Retail Price) - along with a whole lot of the usual stuff like size, make/model, etc.
They plan on implementing the rule on Jan 1, 2026 - and plan on banning any tire in the 1 and 2 star range. (I suspect that is a bargaining position)
I see lots for the tire manufacturers to object to. I don't think the rule will be implemented as published.
On a side note: NHTSA has indicated they plan on publishing a rule on May 23, 2023. This would be the 5th or 6th time they've had a date that came and went. I wonder what they will do now that California has acted.