https://www.michelin.co.uk/tyres/lea...tyre-labelling
Who assigns the ratings to the EU tyres. They have ABC EFG for RR, A the best
"Save up to £110 or 80 litres of fuel over the life of the tyres. That’s for a car fitted with four A-rated tyres driving at 50mph – it uses 7.5% 1* less fuel than with G-rated tyres.
Results can vary with type of car or climatic conditions but the performance gaps are proven."
"1* Performance measured in accordance with the testing methods set by Regulation CE 1222/2009. European Commission’s Impact Assessment SEC (2008) 2860."