I have not found any information in the internet which states anything other than details of production date on tyres are marked as a 2 digit week and 2 digit year code.
Lutz,
As your appreciate trying to get hold of a technical tyre rep from one of the manufacturers on the last Friday before Christmas is not easy, I post a full report on dates etc, when they come back after Christmas.
Recently however there has been a lot of talk about raising the standards of info on the walls of tyres in the EU. The US leads the way: probably after the Firestone debacle - in info; you only have to look at what's printed on Dunlop/Goodyear's to see that.
Moreover Michelin have been badgering the EU for a wear/energy rating to be incorporated, they have introduced numbers such as 320 & 400 on "Energy's" - the problem is there is no way that Bridgestone (firestone) or Pirelli are going to accept something that's being imposed especially when they don't have tyres that meet the competition at present!!
Anyway have a nice Christmas and I'll give you full run down on what Bridgestone, Michelin and Toyo have to say in the new year .
MH