I am finishing my deal for my S55 and I noticed that there are different tires on different S55 on the dealers lot ( they have
6 S55s) Some are R rated and some ZR rated. Different brands as well, could someone help me as the reasoning for this as well as the differences betwween the R and ZR. The sales man told me the ZR are rated for faster speeds but the R rated that are on the car that I selected ride better, is he giveing me a line? Should I push for the tiers to be switched and get the ZR on the car that I am getting? I have alawys had ZR rated tires on my past cars. I thank anyone for any help as the paper work will be finished today and will be delivered tomorrow.

All the 2003's I have seen come with Bridgestone Potenza RE050 tires.

You need to look at the entire designation to fet your answer. A 265 45 R18 Y101 tire is Y rated with a load handling index of 101.

The one car has the tires that you posted the other has Michelin 265ZR18 with a load of 100y. The dealer said he would swap the tires if I want. Any Suggestions on what to do?

Mines got the Bridgestone Potenza's on, they are ok , seem pretty grippy.

If the dealer has both ask to drive cars with both types on see if either gives a better ride or handling ?

Sorry all I know is that Z tyres are rated for over 150mph,
WR are rated to 169 mph, ZR seems to be the new rating to replace Z "Speed Category "ZR" For vehicles with a speed capability over 240 Km/h "