TedH

Looks and sounds SWEET!

MIKE80

Thanks!

Oldguard 7

Here's my wheel/tire combo.

Replica C6 wheels in C5 size, black chrome finish.
Front: 17x8.5
Rear: 18x9.5
Tires: General G Max AS-O3
Front: 245/45R17
Rear: 275/40R18
Van Steel offset trailing arms
2.5" wheel adapters rear
2.75" wheel adapters front







Needs to be lowered. Some forum members may not like the look, but I get many compliments on the wheel/tire combo.

Street Rat

My '81 with some 15 x 8 Weld Pro Stars and 245-60R15 Cooper Cobras.

TedH

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Nothing says classic C3 like big sidewalls. Even without RWL or OWL.

Street Rat

I had the white letters on the outside with my factory aluminum wheels. I thought I'd keep the black theme going. It makes the wheels stand out on this particular car.

redvetteman81

nice look

gbarmore

Performance or not..... Very nice look!

Street Rat

Thanks for the kind words guys.

TedH

I have the 255-60-15's with approx 27.05" tire/wheel height.

From what I have found, my stock 15x8 wheels have:
5x4.75" bolt pattern
4" backspacing

Is this correct for bolt pattern and backspacing?

I've run the 17" tire sizes through a tire height calculator and the 255-50-17's align to my 255-60-15 tire height of 27". All of the three other sizes are close but are off:

245-45-17 has 25.7"
255-45-17 has 26" height
255-50-17 has 27" <========
245-55-17 has 27.6"
255-55-17 has 28"

Now, I want to know if American Racing 17x8 wheels require adapters or if they will fit without.

Would I just need to get 17x8 wheels with 5x4.75" pattern and 4" backspacing to fit with same dim's as my 15x8 wheels/tires? Adapters required?

I note the following wheels have the 5x4.75" pattern but 4.5" backspacing and are supposed to fit the C3 without modifications. They appear to be same SLP wheels others have installed:

SLP Performance ZR1 Series Chrome Wheels 81003


I am partial to the AR 105M's in Anthracite

I may go ahead and upgrade the wheels/tires this Summer...

ONLY IF I can find a decent domestic tire that fits. Right now, I've seen Hancook, Nitto, Kumho and BFGoodrich. What's with the poor selection of tires in this size? Gets me wondering if the 255-50-17's are going the way of my 255-60-15's...

TedH

I see 255-45-18's have greater availability and have the same 27" tire height.

Question: Is there an 18x8 wheel (like the 17x8) that works with the C3 without adapters?

Would I just get 18x8 wheels with 4.75" bolt pattern and 4.5" backspacing?

vetteman1981

Yes there is plenty of 18x8 wheels that will work without spacers/adapters. Like my Coys C5 18x8 with 4.00 back spacing, see pics in this thread.
There are other brands of wheels that offer 4.00 back spacing, Foose is the only one that I can think of off hand. You just have to shop around.

Now with 4.50 backspacing the wheels will have a tucked in look, some people like it some don't. I have seen 1980 - 1982 Corvettes on the forum with the same wheels with 4.50 back spacing and the wheels looked more tucked in on one car than on the other. That's why why I went with 4.00 back spacing. I just didn't want the gamble. The good news is there is no rubbing from what I have read here on the forum with 4.50 BS.

Yes you can get 18x8 with 5x4.75 bolt pattern and 4.00 or 4.5 BS. You should not have a problem.

TedH

I need to take a look at some of the C3's on the forum with the 18x8 wheels with 4 & 4.5" backspacing. I'm leaning in that direction (255-45-18 tires and 18x8 wheels with 4-4.5" backspacing, 0 offset) as I could keep trans calibration/ride height of my C3.

Switching tires and wheels does seem to involve many more decisions than what brand of wheel/tire. True learning experience

TedH

Do you have 1-2 pics from back and front corners to see how the tires fit in the wheelwells (ie. sidewall in comparison to fender lip as well as maybe a pic showing clearance from t-arm/shock/brakeline bracket)?

I'm leaning toward that wheel and tire size (18x8 with zero offset and 4" backspacing with 255-45-18 tires) to get combo close to the outer dimensions of my 255-60-15's.

TedH

If I can find this fitment in a Torq Thrust M (anthracite) wheel, I may be moving up to 18's in 2014-2015.

I like the greater number of tire options in this size over the 255-50-17 tires. (both... 255-45-18 and 255-50-17 are 27" tall).

vetteman1981

No I dont have any pics but I can get some for you either tonight or sometime this weekend.

TedH

Thanks. How does your C3 handle around town and on country roads?

Did you have to get an alignment when you upgraded to the new wheels/tires?

vetteman1981

From what I can find a 4inch back space is the same as -12mm offset for an 8 inch wide wheel.
Here is a chart that I found.

https://www.google.com/search?q=whee...iw=983&bih=548

vetteman1981

I have only driven the car about 6 or 8 miles sence I put on the wheels on Jan 1 of this year and that was on a four lane Hwy. It did seam to have better stearing responce and firmer ride, not harsh at all.

I have not had it aligned yet will do so soon. I have heard that you should when you make the switch.

TedH

I like this tire. All-season, good treadwear and a US tire company:

255/45/ZR18 XL103W 400AAA COOPER ZEON SPORT A/S TIRES

http://www.rims4less.com/proddetail....5fbd3471752bbb

I ran a set of Cooper "Discoverer H/T Plus" (20") on my 2003 Silverado for close to 45K miles. No issues and very good quality. Was nice that my my lady friend (at the time) got about 35% discount. I'll definitely buy Cooper products again. I have pair of their Mastercraft Avenger G/T's on back of my C3 currently. Zeon Looks like a quality tire.