Tire shop error... Z on front, V on back. Realistically is this problem?
 

Discount tire installed my Kumhos yesterday. While cleaning up the car today I noticed that the fronts are Z rated, but the backs are V rated.

Of course when I called they said they would replace the rears with the correct Z rated tire. I was just wondering at what point would this mismatched speed rating cause a problem. Would I notice any handling difference on Z vs V or would they just fail at different points?

According to the tire rack...

Speed Rating - Miles/Hour - Kilometers/Hour - Typical Use
V=149 MPH, 240km/h, Sports Cars
Z=149 MPH, 240km/h and over, Sports Cars

I wouldn't worry, unless you do.. Then get the right ones.

I just got my Kuhmos Victor Racert V700s... WHOOPEEE!!!
They were just literally dropped off about an hour ago!

I would get the Z so they all match, IMHO.

My new BMW was picked up with 3 Michelin tires, and one Pirelli tire. I had the dealer changed it all to Michelin

If there is a different life expectancy number on theidewall of 'V' and 'Z' tires, then there is probably a difference in the softness of the compounds used ...

Did you get a good price?

If not, change 'em

I would DEFINATELY change a different brand or model tires out from left and right. Back to rear is ..OK. But predictability is no longer there with different front and rear tires.

Get them changed!

Speed ratings are misleading. The biggest difference with different speed rated tires is in the sidewalls. The higher the speed rating, the stiffer/more sturdier sidewall. This will greatly change the handling characteristics. No tire shop should put on tires that have different speed rating. They should have payed more attention. Thats one of the first thing they should do while they check the tires sizes.

They were very sorry. They might not have paid much attention since the tires were sent from the warehouse together.

Discount Tire never questioned the need to change them... I just wondered what were the ramifications of not changing.

And I did get a good price. $392 for the set including tax and installation with lifetime balancing.