Wheels & Tires - What exactly does ZR on my tire stand for?

On the side of my tire it states 265 35 zr18 ihave always wondered what zr and xr stands for i know what it means but what does it stand for.

S -- 180km/h or 112mph

T -- 190km/h or 118mph

U -- 200km/h or 125mph

H -- 210km/h or 130mph

V -- 240km/h or 149mph

W(ZR) -- 270km/h or 168mph

Y(ZR) -- 300km/h or 186mph

ZR -- Above 300km/h or 186mph

Opps.... just re-rad your post.... don't guess that helped. :(

Opps.... just re-rad your post.... don't guess that helped. :(

its ok man i was just curious what it actually stands for if it stands for anything at all but i am glad you no (or did ur research) what it means cuz i didnt no exactly the mph it can with-hold but all of it is interestin. if anyone posts a reply to my threads they are always helping me. thanks man. i am glad someone out there knows what it is.

nothing, it is just a way of rating them

It Means you can go Nice and Fast without worrying about a blowout. *Nails are exempt*

Pretty sure its Z RATED. Thats where the Z R comes from. Maybe not - but it sounds good right?

Just a rating, basically if you have a tire that is not designed for the speed your driving, then slow the heck down.

Z is the speed rating. R stands for radial. Y and W rated tires will also have ZR in the numbers because Z was believed to be the highest possible speed rating. Then the W and Y's came out. So for whatever reason they leave the ZR in there.

Z is the speed rating. R stands for radial.
He's got it.

I should hope so. I sell tires for a living ;)

thanks

don't think the cts-v has to have the zr i can drop down a rating

don't think the cts-v has to have the zr i can drop down a rating

im pretty sure they cane with Z rated tires from the factory. you can drop a speed rating to V. i would not recommend going any lower than that

zealous ricer

AR 15 has it correct. Z is the speed rating or and the R stands for radial. Most Y and W will say ZR as well, just like he said.

When they created the original ratings Z was the highest and nobody thought that street cars would end up with tires that needed anything better. When the newer cars needed tires to handle speeds better than "149+" they broke the Z category down with W and Y. Street cars probably won't need street tires with ratings significantly above 186mph so perhaps this rating system will stay safe. :)

its a secret