zr or r rated?

[prm]

Just had 2 new tyres fitted on the front of my e280cdi sport. The old tyres were 245/40/zr18, the new are 245/40/ r18. Is there a difference between thre zr and r , and if so what should be on my sport?, thanks

 

[whitenemesis]

Speed rating usually comes after the tyre diameter (the r18 in your example)

See here for rating symbols

http://www.blackcircles.com/general/speedrating

 

[prm]

Yep, 93Y after rim size. Just wondered what difference was between ZR and R?

 

[Richard Moakes]

There as been a change in how speed rating is marked on tyres.

The old system had a size such as xxx xx ZRxx where the letter Z indicated the speed rating of the tyre and could be a V,W,H,T etc...

The new system has moved the speed rating as follows: xxx xx Rxx yyZ where yy is a load rating such as 95 and the Z character is a speed rating.

Just to make things confusing, Z isn't used any more, the high speed ratings are now W and Y, so be assured those Y rated tyres you have just fitted are as good or not better than the Z rated tyres you had fitted before.