What is the disadvantage of running 315/35/17's on the back of my 92'?
I want to put the grand sport wheels on my polo green 92'.
What are your thoughts on this?

I have experienced an added push when doing spirited driving around corners and autocrossing. This is probably the result of the extra traction from the wider rear tires.

A little more unsprung weight in the rear also.

Basically the wider the tire the more power it takes to make you go faster. I dont think the difference betweek 275's and 315's will matter too much with our cars though. I knwo it matters with real race cars.
Only bad thing I noticed since running 315's on teh back is that in rain its a LOT worse than the 275's from before.. LOL

From a purely scientific approach i guess the following would make since
1) More tire on the ground equals more rolling resistance, take more to keep your car at speed. Probably not much effect on anything except gas mileage and probalby so small of an effect you would not notice.

Oh yeah will those fit within the wheel wells of the car. Can probably add a few nicks in your quater panel for all the garbage kicked up by your tires.

VET 350, Goody has it right. But if you are not using the car for competition, you are not likely to ever notice the push. All US manufactured cars have understeer designed into them to protect the average (below average) driver.
A 315 in the rear on a GS offset 50mm 11" wheel will give you the look and performance you probably imagine. Just make sure that you have proper performance (alignment)specs, and a mechanic willing to stick to *your* specs.

[This message has been edited by h rocks (edited 07-24-2001).]

[This message has been edited by h rocks (edited 07-24-2001).]

[This message has been edited by h rocks (edited 07-24-2001).]

A lot lighter wallet! http://www.corvetteforum.cc/ubb/biggrin.gif

I feel the car handles alot better "all around" w/315's........I'll Never go back to stock size...........why does a ZR1 have 315's............ http://www.corvetteforum.cc/ubb/smile.gif

315's are great. Rain can become a bigger problem than normal though because the wider the tire the more "ski" you have back there. I have had the back end slide out on a turn with no acceleration and very little momentum. Ask R94LT1.. he was in the car at the time!!! http://www.corvetteforum.cc/ubb/biggrin.gif. (remember that.. hehe). Anyway. Better hooking up, lower top speed to due to resistance, and a lighter wallet are the other things you will see. Just like what some people have said above.

One more thing to add: You always put the widest tires under your wheel wells when looking for more traction. Wheel spin looks cool, but is a waste of forward motion.

Don't forget that if you go to the wider tire you may have to recalibrate your speedometer. Go to www.tirerack.com to see the difference in tire sizes in terms of diameter and treadwidth.

I have the 315 on mine, and really like the look. I put the GS flares on them also. Only problem I see is a lot more dirt on the back side of the car.

I save my 335's ( on all 4 http://www.corvetteforum.cc/ubb/biggrin.gif ) for the track. On the street it follows the ruts too much. If it rains alot wear you are, get some tires that shed water pretty good. Obviously I save the autocross tires for dry tracks http://www.corvetteforum.cc/ubb/biggrin.gif

I wrote a program a few years ago to calculate tire sizes. I did it for my own use, but I received so many requests, I put it on a server:

http://www.geocities.com/koottung/tirewizard.html

It is called TireWizard.

Good luck!


[This message has been edited by pzoom (edited 07-25-2001).]

as far as 315/35 versus 275/40
the overall tire height is virtually identical (theoretically)

315 is taller by one half of a millimeter!
taint nuttin

http://www.corvetteforum.cc/ubb/smile.gif

The only disadvantage is it takes more RPMs and fuel to smok'em. But the responses you get from others will make up for it http://www.corvetteforum.cc/ubb/smile.gif.

I have Pirelli P7000 315/35 ZR17 tires on black GS 17 x 11 wheels all around on my 96 coupe. The rear 315's wore off about 0.5" of the inner plastic wheel well shields, but they clear the Walker dyno max mufflers by an inch, and before that they cleared the Flowmaster mufflers by about an inch. They look great and fit under the rear fender. I haven't had any problems in wet weather, and it was raining hard at the WSCC convention in Yerington, NV.

I think the right tire brand takes care of the hydroplaning. I run Michelin Pilot Sports and find them fine in the rain. Besides those big tires just look pretty darn cool.
Don

One can't rotate the tires...assuming you would run the 275 or 285 tires all around. I can see much less life out of a set of tires that only occupy the rear of the car.

Like what was said before-adds more weight too-each of my rear tire/wheel assemblies added 9 pounds(18 total). I certainly can't feel it, but doesn't help with the et's. Although recently to the dragstrip, I ran 13.35 four times in a row and all within .01 of each other...I've never done that with a stickshift car. So the larger tires gave noticably better traction (Pilots).

Do the fronts rub at all. Nice set up [img]http]//www.corvetteforum.cc/ubb/biggrin.gif[/img].