atljar

Per tire Rack weights on Pilot Super Sports....

275/35/18 and 325/30/19 weigh 114lbs total.
285/35/18 and 345/30/19 weigh 134lbs total.

Do you guys that switched to oversize feel that is was worth the 20lbs rotating weight gain? That's a TON!

AzDave47

Your weights are different from what I saw at TR: http://www.tirerack.com/tires/tires....ot+Super+Sport

I see 26# vs 28# each on front and 32# vs 35# each on the back for 116# vs 126# or 10 pounds per set. for that you get 1.2" more total front tread and 1.8" more total rear tread which should increase grip quite a bit with a good performance alignment with each set.

I can also say that many make the change for "looks" and that is one of the reasons that the Invos are a popular choice (low cost, quiet ride, long tread life and good looks, but just OK performance).

atljar

126lb for the oversize, I cant add I suppose. Back to grade school for me No idea how I did that.


However, they list two different tire weights for the 275 fronts. One is 25lb and the other is 26lb???

If you enter Corvette Z06 as model, and then click Super Sports, and then the spec tabs.... They list the two tires that fit your vehicle at the top. Weight there shows 25lbs. Scroll down further and find the exact same tire where it shows all available sizes, and they list it at 26lbs. Odd.



So we are now talking 10-12lbs difference. That, IMO is still significant amount of unsprung weight. I'm curious if anyone has ever actually had both sizes and could quantify the performance/traction gains in anyway

AzDave47

I see that and the 25# tire had 0.4 more tread width mostly eliminating the 285 tread advantage.

TR used to specify when tires were car model specific, but since they went to their new web site format, they have lots more fluff and make it more cumbersome to view the details of more tires at the same time.

reasonable suspicion

I compared the bigger ss sizes to the stock runflats when I bought mine. I wanted the bigger sizes, and I saw they weighed less than stock, that was good enough for me. Figured I was going to get lighter weight rotors at some point as well anyway.

nhpln

Putting wider tires without getting wider wheels has questionable value in terms of traction and grip.

However, with wider tires, as you've observed, you do get:
1) weight gain
2) less road feel and less precision

AzDave47

Both the 285 and 345 PSS are recommended by Michelin for the stock 9 1/2 and 12" rims. What you say could be true for a tire that is too wide for the rim, but M doesn't think so in this case.

Vito.A

Interesting. I just compared weights:
Goodyear Supercar G2 275 front 28#, 325 rear is 32#
Goodyear Eagle F1 Supercar 275 front 29#, 325 rear is 34#
Michelin SS 285 front is also 28#, 345 rear is 35#
Regardless, the Michelin is a far superior tire in both performance and tread wear.

Vito.A

I disagree. The Michelin is a far superior tire regardless of size. It's not the few mm of width that increases performance, its the vastly superior engineering and construction, not to mention they last 2-3 times longer.
If you actually measure a Goodyear Supercar 325, it is wider than a Michelin 325 rear, so increasing to the 345 width Michelin actually makes it only slightly larger than the OEM tire.

nhpln

No disagreement here. I run the Michelin PSS in stock 275/35/18 325/30/19 sizes and they are an excellent street tire. But I don't care to run the 285F 345R PSS for the reasons I mentioned above. Bigger is not always better.

AzDave47

I have the 275/325 PSS and will probably replace them with 285/345 PSS. I found the 275/325 combo understeer more in steady state corners at HPDE's than my previous 295/335 NT-05's. The PSS have higher grip, but the 275/325 handling balance was not as good as the NT-05s in the 295/335 setup which is why I will try the 285/345 combo, hopefully achieving more front grip.

The more dedicated track guys they go with a 315/345 combo on appropriately wider rims, but as I indicated earlier the factory 18/19 rims are in the width recommended by Michelin for the 285 and 345 tires.

Frequently wider tires can be a drawback on lower HP cars as they do not have the power to overcome the added cornering drag of the wider tires. The Z06 does not have that problem. Proper alignment for the targeted use can also make a difference.

nhpln

Hope the 285/345 combo works out for you. Will be interested to hear what you think after you get some miles and track days on them

AzDave47

next spring

BLW BY

Just to throw more fuel in here, Michelin just came out with a 295 for the front. Same weight as the 285 and a closer to OEM front/rear size ratio.

Win / Win for us guys with lighter and wider rims.