Mad4slalom
Well-known user
Hi all, picking up some white letter tyres for the 72, am thinking of going up one size to 235/70/15 . Anyone else run these and is there much difference in height / width. ? TiA 
Tyre sizes.
- Thread starter Mad4slalom
- Start date
Steven Smith
CCCUK Member
I find this site really useful for comparing tyre sizes:
tiresize.com
TireSize.com - Compare Tire Sizes, Specs, Prices & more
Use our tire size tools to calculate specs, speed, gear ratios and more. Browse tires by size, vehicle, or brand and compare prices online all in one place.
Roscobbc
Moderator
Later C3's have re-profiled, larger fender openings and can run with 255 section 60 series tyres (perhaps 70 series?) - your '72 itself will have fender opening more flared than very early C3's......I would have have thought you'll be OK........but Vettes do often vary in terms of wheel placement vs fender lip and chassis clearance. 235/70/15 is 28" diameter - commonly used 235/60/15 at 26" diameter is too 'short', doesn't 'fill' wheel openings correctly and will change gearing a little. Optimum diameter is 27" (ish) the 70 series tyre at 28" could possibly catch fender openings and rub chassis on full lock?. Perhaps find someone with 235/70/15's and try on yours before committing to a purchase?Hi all, picking up some white letter tyres for the 72, am thinking of going up one size to 235/70/15 . Anyone else run these and is there much difference in height / width. ? TiA
Mr. Cricket
Committee Member
215/70/15 front 225/70/15 rear, 71 Corvette. I find the taller wall (70) than typical (60) fills the opening better and removes some of the stock 4x4 look. That and a slight lowering helps too.
I went with Redlines as I was sick to farkin death of trying to keep the RWL white/clean with little success.
Gone back to the Derby Caps & Beauty Rings now too
I went with Redlines as I was sick to farkin death of trying to keep the RWL white/clean with little success.
Gone back to the Derby Caps & Beauty Rings now too
Mad4slalom
Well-known user
Looking great, good choice on the caps and rings too imo, I had the po2’s but always niggled me that they were not quite as perfect as the vaps and rings
Mr. Cricket
Committee Member
I quite like the look of the PO2's but they're a lot heavier than the poverty caps. Those in the pic above I restored and converted from Impala covers and are now wall hangers. I came across a set that had billet aluminium centres that were/are perfect and had to have them so I ran with them for a couple of years before taking them off..
Mad4slalom
Well-known user
Love those redlines with the red paint
I Had already collected tyres when I saw your post. I had seen posts of people running up to 255,s with no issues but maybe they were 60 series not 70🫣
I am back home now and just held one up against the car. They are A half inch bigger all round so I am hoping they will , like you say fill the arch a bit more without any clearance issues
Mad4slalom
Well-known user
I wondered why you run 215 up front instead of 225, wondered if it is not a power steering car and it was to lighten the steering or you just liked the staggered look
Mr. Cricket
Committee Member
Has PS but yes, I like the staggered lookI wondered why you run 215 up front instead of 225, wondered if it is not a power steering car and it was to lighten the steering or you just liked the staggered look
Mr. Cricket
Committee Member
if you went with raised white letters I've found a bulk buy of 30 Brillo pads for just a few quid is the best thing for keeping them somewhat white although mine are white lines not letters. I have 10 different white letter cleaning compounds - Bleche White, Raceglaze etc, etc, pants the lot of them since environmental restrictions forced the manufacturers to omit the 'good shit'Love those redlines with the red paint
I Had already collected tyres when I saw your post. I had seen posts of people running up to 255,s with no issues but maybe they were 60 series not 70🫣
I am back home now and just held one up against the car. They are A half inch bigger all round so I am hoping they will , like you say fill the arch a bit more without any clearance issues
Mad4slalom
Well-known user
Just been googling who has been running 235/70 ‘s and some are experiencing rub on front full lock. I am wondering whether, before I fit them to exchange them for 225’s to avoid any issues. Do you think the larger diameter may just not look right? Once I fit them then I am stuck with them
Roscobbc
Moderator
Its not the increased overall diameter of the tread of the tyre as such that can be the issue - its more the overall diameter of the tyre as measured at the outer edges of the tyre tread when turning the steering left and right (and both the inside and outside edges of the tyre).
As the wheel/tyre turns left or right the inner/outer tyre edges transcribe a larger 'arc' from upper/lower steering arm theoretical pivot point than the centre of the tread.....and obviously even greater if using a 235 wide tyre with a 70 section vs 60 section (and/or wider tyres)
I use a 255/45/18 tyre on a same as stock width rim (8" wide) rim stock backspace/offset measurements. Tyre is 27" diameter.
The tyre section of a low profile tyre has much squarer thread/sidewall corners than 'old school' higher profile tyres with the 'corners' of the tyre transcribing an even greater measured arc of movement than the above 60/70 profile examples.......so one really needs to check for 'contact' with chassis on full lock and lower rear of the wheel openings of front fenders......if that all makes sense?
As the wheel/tyre turns left or right the inner/outer tyre edges transcribe a larger 'arc' from upper/lower steering arm theoretical pivot point than the centre of the tread.....and obviously even greater if using a 235 wide tyre with a 70 section vs 60 section (and/or wider tyres)
I use a 255/45/18 tyre on a same as stock width rim (8" wide) rim stock backspace/offset measurements. Tyre is 27" diameter.
The tyre section of a low profile tyre has much squarer thread/sidewall corners than 'old school' higher profile tyres with the 'corners' of the tyre transcribing an even greater measured arc of movement than the above 60/70 profile examples.......so one really needs to check for 'contact' with chassis on full lock and lower rear of the wheel openings of front fenders......if that all makes sense?
Mr. Cricket
Committee Member
Yes I can see that being an issue..
Let me see if I have a better pic of mine......
Mr. Cricket
Committee Member
There you go
Before the redlines..
The yellow one was stock height but with the same size tyres as the red one which you can see with the distance from the top of the tyre to the wheel arch lip:
Before the redlines..
The yellow one was stock height but with the same size tyres as the red one which you can see with the distance from the top of the tyre to the wheel arch lip:
Mad4slalom
Well-known user
Mad4slalom
Well-known user
Gone back to 225 to be safe
Mad4slalom
Well-known user
Just trying to clean off the blue coating 
Mr. Cricket
Committee Member
I hope for your sake they don't turn brown over night like my last set of the same.
Clearly the Mrs was out shopping to have the tyres in the house
Clearly the Mrs was out shopping to have the tyres in the house
Mad4slalom
Well-known user
Chassis and wheelarch clean , adjust handbrake shoes then get the wheels back on. 
