So I went onto Tirerack.com and saw I could order my tires for really cheap (I only needed two since my Front tires
were thrashed). I order them and notice one thing is different and I didnt think twice about it.

The tires I have on the back of my car are 225/40ZR/18 88W
and my front tires will be 225/40WR/18 88W

The only thing that differes is the 40WR. I have no idea what that means.. it will still be ok, right?

 

i have heard that the Z used in the rating of performance for the tire is an old style rating. new style ratings use W and Y's. your new tire has a W that should be the equivalent to the old Z.

 

Sweet... thanks!!

Thats what kicks *** about these forums... I can always depend on a quick answer.

 

well, zr means z-rated, so wr means w-rated

not sure what it means or whats the difference, if there is any...maybe all season low pros...i kno alotta zrated u cant drive in winter, maybe wrated are all season, not sure man

 

damn theres already a reply, lol im typing slow today...

 

yes, they are a speed rating, and w and y are the same as z, but if you have quattro you really shouldn't be replacing two tires, you have to replace all four, unless the ones you aren't replacing are in near-new condition.

 

i got two front tires. then 2 weeks later two rear tires.

I wish I had either more power or less grip in the rear because I can't put it sideways anymore.

w, y and z are high speed rating tires. They can handle a constant 120+ mph.

 

The back tires have alot of tred left, if not near perfect.

I thought the W, by the 88W, was the speed rating. That W meant you could go 168mph. Sooo... the 40WR and 40ZR is the speed rating?

 

the 88 in 88w is the load index (how much weight the tire can handle)

here's a chart that shows you the different speed ratings..

http://www.tiresafety.com/size_class/size_nav2a.htm

 

225 (tire width)/40 (sidewall height) ZR (speed rating)/18 (wheel size) 88W (load index)