Just watched a

advert on the box, their latest tyres can save us up to 80 litres against the horrible petrol pump.
What they don't say, (unless it's in that minuscule writing used by Companies as a get out clause), is over how long.
If it's saving us that much between fill up's that is fantastic.
If it's over the lifetime of the tyres, I wouldn't have thought it worth mentioning.
I've looked on their site but can't find an explanation, do any of you know what figures they are using to be able to claim what to me seems a vague figure?
Michelin - Michelin Energy Saver