2ooo-C5

I have read a bunch of posts with 17's and 18's, 18's and 19's but there is very little on 18's all the way around.

I have 18" wheels all the way around.
I have been running pirellis. But I want to go to something I can actually
buy in America and stop running these used ones.

So what will fit?

I'm thinking a 295x30x18 on the front and 315x35x18 on the rear.
No idea if anyone actually makes those.

I do not run with traction control on, don't care about ratio.

Thanks for your input.

chetly

I wouldn't run anything bigger than a 265 on a 9.5in rim.

If your going to want to run a 295/305/315 you'll need a minimum of a 10.5 inch rim.

2ooo-C5

The 315/675-18 fit great on a my wheels, ran them for 2 years now.
Love the tires, just can not find fronts to match.

I have seen guys fit a 295 under the front, but I don't know what height it was.

FuriousDonuts

If you have equal sized wheels on all four corners, why not run the same-sized tires so you can rotate all four corners?

2ooo-C5

I would love to... trying to figure what I can fit under the front.
Still don't know what will fit.

My rear tires last a year and my left front lasts 1 day.

Scooter70

Keep the diameter between 25-26" and you can fit anything up to 305 wide with a 10.5-11" wide wheel. 315s fit in the front but you may have to raise the ride height. On a 9.5" wide wheel I wouldn't go wider than a 265-275.

If you're tearing up a front tire in one day you probably need more camber. What are your front alignment specs?

2ooo-C5

sounds like P295/30ZR18 R7 all the way around might be a good set to try this year.
I love the idea of all 4 the same to get more use out of the fronts.

Im afraid that will be to small on the rear. 600 rwhp is hard to make stick to the ground.

klodkrawler05

Do you have base model wheels (which are 9.5" wide) or z06 wheels? (which are 10.5" wide)

that will make a difference on tire size recommendations. In that regard, compound will make more of a difference than the size stamped on the side of the tire.

I've tested 275 bridgestone RE71 tires that put the power down as well as a 315 bfg rival S tire.
The bridgestone's measure nearly exactly as wide as the 295 rival as well further showing the irrelevance of number stamped on the side.

2ooo-C5

I just want to know the widest / tallest tire that fits under the front of a C5 corvette.
Once I know what fits I will decide the best size and brand for my needs.

Im pretty sure a 305/30r18 will fit. Was hoping someone would tell me for sure.
Wheels are $50 a piece. Tires are $350 to $800 a piece.

I figure R7's. I don't want a street tire. I have street tires and wheels.
Saying I am looking for a race tire will start a huge debate on my driving skill and I will get
told to sell my car, buy a Miata and learn to drive that before I even buy a corvette.

klodkrawler05

Ah well that's an entirely different can of worms.

305's fit under the front of a c5.
315's will fit under the rear.

for a track only setup, 315 fronts and 335 rears will work and are what myself and a fair amount of other guys run.

however since you know so much about tire selection you already know you're not squeezing 335's onto the stock 9.5's.
Well you could if you subscribe to the old school train of thought of throw as much tire on a wheel as you can get to seat but pretty much any and every private/public tire test in the past 5 years shows that contact patch is mainly affected by wheel width.

So if you're dead set on running those $50 9.5's you'd be wise to buy tires that fit on that size wheel (a 275-285 is about it unfortunately, anything wider will wallow like a pig and cost lap time and extra dollars)

Get the benefits of better steering response and correspondingly faster lap times while at the same time putting the money you saved aside for a set of $200 a piece z06 rear wheels or something more expensive and even wider.


Note: I assumed when you mentioned R7's you're looking to do roadcourse racing, if you're looking for drag racing and highway pulls then by all means disregard my comments and slap whatever looks cool on there.

joes68340s

Im running those wheels just don't know what the best tire for autox . 200 tw. Sorry for hijack.

FASTFATBOY

I put 305-650-18 Continental slicks on my car today, haven't run them yet but I will this weekend.

I don't see much more tire working "right" on a 18x10.5 Z06 wheel as these are slightly "pooched" out.

Scooter70

Look at Hoosier's chart and note the Recommended Rim Width column. Anything wider than the 265/645R18 requires a 10" or wider wheel. If you're stuck on using the 18x9.5" wheels, that's as big as you can go. Do not try to squeeze a 305 on to that wheel. It will not perform properly and will be unsafe. A 305 will fit on the front of the car (ON THE RIGHT WHEEL). If you want to run wider tires you need wider wheels.

https://www.hoosiertire.com/specrr.htm#ROAD RACING SLICKS- RADIAL

2ooo-C5

Then I could run 305/30r18 all the way around the car on the right wheels.

Thank you. That is the answer I was looking for. Simple and to the point.

FASTFATBOY

10.5 wheel being the limit, at least for a Continental slick, it bulges a little bit on mine.

2ooo-C5

Now, that I have the answer to the question I asked.

I agree a 305 and up is pretty wide for a 9.5" wheel. I don't mind getting larger wheels.
Wheels are cheep compared to tires.

But... what is up with the pirelli 315/675-18's
Are they not really 315?

They fit great on my 9.5" wheel. I was worried about them being to wide when I bought them.
Explained that to the tire shop and they felt the tires fit the wheels very well.
Honestly, they had a hard time pulling them out to make them seat.

They wear great. Grip very well. I see no reason to change the size on the rear.
Issue is I cannot afford them new for the front. They are $800 a tire new.
I get them used for $50 a piece.

Never tried a new set of slicks. I figured this year I would get a full set of new R7's
As I said, I wanted to know the widest tire that would fit under the car. I will then get
the wheels needed to make them fit.

Corvette place around here sells me factory wheels for $50 to $200 a piece, depending on style.

My guess is those 315 are not really 315. They don't look much wider then the 285's I use
on the street. Will have to measure them one day to compare.

FASTFATBOY

Hard to see, but the sidewall is pulled in at the bead. This a 305-650-18 on a 10.5 inch wheel.

2ooo-C5

On the street that is fine. That might be why the tire shop did not care.
My rears taper in a little more then that. They are a lot taller tire.

So on a race track, I take it that is not fine.
What does it do?

Not arguing... Im trying to learn. I will gladly get the right size wheel.
Road racing is a lot different then anything else. Little things matter a lot more.

FASTFATBOY

The tire "domes" the tread when the wheel is too small, similar to the curvature of your head. You're carrying around a bunch of tire you can't use.

Because the sidewall is pulled in like that it will work the sidewall a lot harder and build heat in the tire.

Vettechris996

I'm running 315/30-18 NT01s on the track and everything fits great. Car is lowered on stock bolts with a camber kit. Looks great with all that tire too!