Bushman66

I want to keep the stock rims and tire sizes, 2004 Z06. This pretty much leaves Michelin PS2's and the OEM Goodyears (absolutely won't run these).

Anyone here running 295/35-18 Michelin Super Sports in the rear, with 265/40-17 Pilot Sport PS2's in the front? Seems like it might be a decent combination, with the Super Sports offering longer life and better traction, better balancing wear? The Super Sports are significantly cheaper than the PS2's (and I believe the rear 295 PS2's are Porsche N-Compounds, creating a mismatch anyway). Thoughts, experiences?

Thanks!

Evil-Twin

You dont get longer life with better traction tires.. That's a trade off.. tread life numbers are not transferable or relative to different manufacturers.
You can have better traction or longer life but you cant have both. rubber is for traction but wears out quickly, carbon is for longevity but its hard and is a poor coefficient of friction. Touring tires are called touring tires because they are designed to take long trips on super highways, they have 60 % carbon and 40 % rubber... ( more carbon than rubber ). Performance tires, sticky tires high coefficient of friction have 60 % rubber and 40 % carbon. or a variant. with less carbon and more rubber they do not last as long. Dont compare tread life numbers from one manufacturer with thread life number from another, its only an internal company comparison. there is no Federal DOT standard for tread ware numbers.
Bill aka ET

Bushman66

Thanks Bill. I am looking at the same manufacturer (Michelin). The Super Sports (Rear) have a treadwear rating of 300, vs the PS2's (Front) treadwear rating of 220, so it theoretically should be apples to apples. However, Michelin's own website lists the Super Sports as having superior dry grip, which is confusing, given the logic you state above (and the way I understand treadwear ratings as well).

dreamr616

I'm in the same predicament. I started a thread the other day in search of reasonably priced tires to replace the ones I currently have. You might want to check out the posts in it. They may be useful to you.

https://www.corvetteforum.com/forums...z06-tires.html

z06801

I think having different tread ratings front and rear will upset the balance as you approach the limit and for sure I wouldn't want the softer tire up front, with a softer tire in the rear for traction you'll just a have a push closer to the limit. Softer tire in the front you could have a dangerous oversteer as you approach the limit.

c4cruiser

I just bought a set of Z06-size Michelin Pilot Sport PS2 tires for my '02 coupe to go on my OEM Z06 wheels. I bought 275/40-17 for the fronts and got the 295/35-18's for the back. The 275/40-17 tires were easy to find but the 295/35 Michelin PS2's were very hard to find. Tire Rack had the 275's, and Discount Tire found a pair of 295's but one was in Ohio, the other in Texas.
The Michelin PS3 seems to be available but not in a 295/35-18. Both Discount and Tire Rack can get you 285/35-18's and that was what they recommended for the rear wheels.

acroy

If mixing, I would put the 'less sticky' in front, as this will give understeer, which is generally regarded as a lot safer/more predictable than oversteer!
I currently have Toyo T1 in back (stickier) and Toyo Proxes 4 in front (less sticky). Yes the car understeers a bit, however the Proxes 4 are so progressive and 'talkative' it is very easy to manage. The limits are still very very high More than plenty for street driving.

Bushman66

Reading through the various threads, it appears another option is the new Conti ExtremeContact Sports, seem to be getting a lot of good reviews. Being in AZ, wet grip is not an issue, and the new Sports are more weighted toward dry grip and handling. But...that leaves the classic C5Z tire question, 255 or 275 front tires, since they aren't available in 265.

dreamr616

Been doing lots of research on tires for my Z as well. If you went the 275 route, the contact patch would be wider but the sidewall would also increase. Some have said that bigger sidewall looks a bit awkward compared to the 295 in back. Some have said that ok. The 255 will "look" better because the sidewalls between the 255 and 295 will be more similar but the contact patch will be narrower. I'm kinda leaning toward the 255 because I don't want that big looking sidewall up front (more aesthetically pleasing). Or, you could go with Toyo Proxes T1. They're available in stock Z06 sizes (265 and 295).

There are a lot of CF threads about going the 255 or 275 route. It's about 50/50 on which way to go with. Some want the wider tire and don't mind the look and some want the better look but live with the slightly narrower tire compared to the 265. Guess it just depends on what's most important to you. Looks or performance.

Hope that helps.

4XLR8N

I believe 10 out of 10 OEM chassis/handling/vehicle dynamics engineers would tell you NOT to mix tires. Different tires have different traction and handling characteristics that can yield unpredictable and/or sub optimal results when mixed.

Now, if all you are doing is cruising around and not really pushing your car, I am pretty sure you can get away with it. Might even get away with it driving your car hard. But it isn't a good idea...

Bushman66

I'm leaning toward the 255 as well, if I settle on the Contis. I think the performance aspect is overblown, since contact patch is related to a lot of things (i.e. 9.5" rim, alignment settings, etc). I'd wager that the turn in is sharper with the shorter sidewall. I'd bet that unless you were at 10/10th's on a track, you'd never notice the difference between the 255 and the 275. So...in the case of a tie, aesthetics would be the tiebreaker.

I checked into the T1 Sports, obtainable, but not readily available, and my guy at Discount called their distributor (I was there when he was speaking with her), the T1's in Z06 sizes are being discontinued in 2019, so that might make replacement problematic if you need a road hazard replacement. He is going to call again today to reconfirm.

killian96ss

I have the Continental Extreme Contacts on my 02Z. They are 275/40 front and 295/35 rear on factory Z rims. The 275 fits the front rims better than the oem 265 did and personally I think the 255 is way too small for a 9.5" rim, it's almost stretched on there, so the 275 is a better option. As far as the tires themselves, they are great. Very good traction and very responsive to steering input. I've got about 10k on them now and they seem to be wearing very good, probably got another 30k in them unless I really start beating on them hard, then maybe another 20k which is still good for a max performance summer tire.

Steve

Bushman66

Great info Steve, can you post pics of your setup? Would be good to see visually, there is a huge variance in tire sizes among manufacturers. I'm interested in the heights of the sidewalls, front and rear to see if there is even a true visual difference between the front and rear, and the 265 and 275's. Thanks!

Found some great info here, that confirms what you are stating above. In the article, the author states, “For ideal handling: when sizing a tire for a given wheel, I usually target a tire’s TREAD width to be as wide as the WHEEL width, or 0.5” narrower than the wheel width.” Looking at the tread width specs on TireRack, it looks like 9.5" tread width measured on a 9.5" wide rim.

https://motoiq.com/how-to-properly-select-and-size-tires-for-performance/

killian96ss

Not the best pic, but the only the only one I have showing front and rear together and yes I know I need to lower it, alot, lol.

Steve

dreamr616

Is that for the 255 or the 275 on the 9.5" tread width you mentioned?

dreamr616

Can you keep me in the loop on the Toyo T1's? Sounds like you and I are in the same book with tire replacement on our Z's. Thanks!

killian96ss

The 275 is the recommended size for a 9.5" rim, but you can fit everything from 255 to 285 on the same rim, 275 is just the idea size based on tread width.

Steve

Bushman66

Steve is correct. If you look at TireRack specs, the 9.5" rim = 9.5" tread width for the 275 Extremecontact Sport. The 255 specs out with a 8.8" tread width on a 9" rim, on a 9.5" rim, it falls just under the "1/2 inch narrower" rule-of-thumb.

dreamr616

So which way are you leaning? 255 or 275?

Bushman66

I may have Discount mount up both so I can see firsthand which I prefer.