I was looking to hopefully just replace my rear tires on the coupe (with 18's) since the fronts look almost new and the rears are a little past the wear bars. I was looking to get some Kumho Ectsa MX's for the rear in 245-40-18 but they are almost an inch shorter outside diameter. I think that will mess with the VDC system a little bit. I have read on other posts that the outside diameter doesn't really matter because it might be different where it is measured from from manufacturer to manufacturer, that I should use the number of revolutions per mile instead. Does anyone know where to get this information for the Kumho's and the stock Michelin Pilot Sports in 245-45-18? Should I just jump up to a 275-40-18 instead to make sure the tires are the same size all around? I think that would make understeer a huge concern with all that tire out back and not much in the front.

I am also thinking about getting S03's, but from what I have read on the Kumho's, I really want to give them a try for a little while, maybe get S03's when the Kumho's and Pilots wear out in another 15K - 20K.

Any suggestions would be appreciated. Thanks in advance.

Dennis

 

275/40s should not be installed on 8" rims, there will be significant tire buldge. 275/40s need 9.5" width rims. Your right about keeping the height and stagger as close to stock as you can. 245/45 or 255/45 should both work. As well as the negative affect on handeling, the smaller tire will also look funny mounted on the car. I know the SO3s come in a 245/45 and a 255/45 size. I know nothing of the Kumhos.

 

I have Kumho's on my rears.. They've been on for about 5K miles now. I love the aggressive tread and they grip the road very well.

As far as VDC problems, the VDC has come on twice the whole 5K miles when it maybe should not of.. I do drive fast alot of the time and the VDC has not been a problem.

You can see pics of the car in my Imagestation album. Its seems to be down right now but you can look it under Baumer.

 

I've had the MX's on my sedan for around 5.5K. The grip well, are predictable at the limit. But they are on the loud side and on all to many surface types, they squeal when I DON'T want the attention. When they wear out, I'm done with them, S-03's for me. If they didn't squeal so much, I'd keep them because of their price point, but that's not enough to put up with their antics. Biggest plus they offered was no noticeable change in ride quality when changing from 17's to 18's.

 

The MX's are loud? Damn, I didn't really know that. I thought that the Pilots were loud on the car...I don't think that I want something that is going to be LOUDER. Hmm, looks like I may have to go with teh S03's then.....

 

You may want to think about Dunlop SP9000s. i just put on a set on my 18" Nismos yesterday - 245/40, 275/40 on 8.5 and 9.5" rims . They seem to handle very well. They're not loud at all. They don't make a 225/45 for the font, but they do make a 245/40/18. For the back you could fit 255/45s on the stock wheels. I really like this tire.

Lou

 

I just mounted S03's to replace my RE040's - really happy with them and they are the correct sizes so no issues there - good luck

 

Since he lives in NY, he should not get the SP9000s. They are completely worthless in the snow, and since the tire is made of a silicone compound, the gripping properties suck when it's cold. I had a set of SP9000s for several years on my old car, but I will not put them on my Z.

I put on S03s over the weekend, and have been pleased thus far. Unfortunately it's been raining ever since I got them, so I haven't had an opportunity to exercise them.