Tyre label economy ratings: where to find details.

[Bill]

All I can find is a vague "7.5% difference between A and G" (on Michelin's site) but I want to compare B/C and E, and there doesn't appear to be a D rating at all. And I know it's a self regulated crock of ste but some detail would be helpful as my motorhome is pretty hopeless on fuel.

[ma9mwah]

"The fuel efficiency/rolling resistance section of the tyre label is calculated by the scale specified in annex one to the regulation and measured in accordance with annex 6 of Economic Commission for Europe (UNECE) regulation No 117 and its subsequent amendments. This is detailed in commission regulation (EU) No 1235/2011 amending regulation (EC) No 1222/2009."

No 1235/2011: http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?...
No 1222/2009: http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?...

[TA14]

IIRC your summary is correct: 1.5% per letter and on a scale of a to g there's no d and no g

[Bill]

Anyone know what class van tyres fit into?

They reckon rolling resistance could account for 20-30% of fuel economy, and in classes C1&2 there is no D, so the difference between C&E could be 20% of SFA or 20% (I'm choosing the lower figure because it's an overcab van and the gearing is short...) of 2 on a scale from 6-12.

fked if I can work it out.

But if Michelin reckon the difference between A & G is 7.5% it has to be less than 5% different.

[Claudia Skies]

It's a simple thing - the rounder the tyre the less the rolling resistance. So tyres which give a hard ride and worse grip are typically more economical on fuel. Avoid.

[Bill]

I'm talking about tyres for a 3850kg motorhome, but thanks.

[TA14]

Try posting in http://www.pistonheads.com/gassing/forum.asp?h=0&a...

[Bill]

Yep, I've already bumped an old tyres thread but I was after details on the labels.

[ecopia]

All these rating on any tyre are manufacturer based there's no general body who test them all and give db information of wet grip or economy every tire do there own tests and fit there own label's