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Discussion Starter · #1 ·
Hi all,

Im looking into getting a new set of wheels and tyres and just wanted to check what sizes I will be able to get away with, bearing in mind my suspension is lowered by 40mm.

At present I have std CSE wheels :205/50/15 which have an overall diameter of 586mm.

I can keep the same overall diameter with 225/40/16 586mm
or 225/35/17 which is 589mm
or 215/40/17 which is 604mm

What would you guys recomend, I would like 17's but im not tied to that, also bearing in mind that some 17" tyres are cheaper than 16" on a higher profile.

What would be the max width that you can go to?

Your comments / experiances greatly apreciated.

Ta

Damian
 

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Well, Scaero supplied a formula for calculating the outer diameter of the tyre based on tyre size and rim diameter. I plugged it into a spreadsheet, and it's expressed so:

diameter= 2 * ((b/100) * a)) + ( c * 25.4)

where

a = profile width
b = aspect ratio
c = rim diameter in inches

So, if your current tyre has ideal wheel arch clearance you want to stick with a tyre that has the same diamter +/1 1mm (ideally).
 

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Damian, those are awfully small for a '96 CSE. My '96 handbook says 195/65/15 or 205/60/15 for a 15" wheel.

An equivalent size in 17" would be 205/50/17 to give you more or less the same rolling radius. If you want to go wider, then 215/45/17 is close, and 225/45/17 is almost spot-on. However, the 225s might rub - anyone know for certain? I'll be doing this exercise shortly myself.
 

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these tyres are definitely too small...
however my aero is on 235/40 x 17's which are great ...they have enough sidewall movement so that there is very little tramlining and the ride comfort is the same .
These are on 7.5 " wheels and I have had no problem with rubbing
 

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Agreed, my CD is running 205/55 R15's. Which if anything are a touch on the small side, these have an outer diameter of 606.5mm.

Does anybody have a reference table for the different possible wheel/tyre configurations for each MY and variant. e.g.

1985-1991 Hatch
1988-1994 CD
1992-1998 CS Hatch
1995-1998 CDE

I'm assuming (from previous comments) the CS and CDE have larger arches than the earlier cars?
 

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Originally posted by Jason (Mr Torque-Steer):
[qb]I'm assuming (from previous comments) the CS and CDE have larger arches than the earlier cars? [/qb][/b]
Yes, the CS/CSE and facelifted CD/CDE ('95-on?) have more clearance in the front arches. I don't think this was the case with the pre-facelift CD.
 

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Ylee, is your Aero lowered (can't remember)? I've been considering which tyres to put on 7.5x17" rims and have been wondering about 225/45/17. From your experience, these should be OK, all else being equal.

235/40/17 are a slightly smaller outside diameter than standard (620mm vs 632mm), while 225/45/17 (634mm) are almost standard. I wonder whether that might make the 225s more likely to rub?
 

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I run 225/50*16's on my aero and the only rub is full lock right against the panel cover in the left wheel arch.

No bump or driving rubbing at all, and it cured lots of the attempted wheel spin and adds a little more surefootedness to the corners.

Andrew
 

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Originally posted by Scaero owner:
[qb]I run 225/50*16's on my aero and the only rub is full lock right against the panel cover in the left wheel arch.[/qb][/b]
I get that even with the standard 205/55/16s


Those tyres should be the same width and diameter as 225/45/17s, though, so maybe it'll be worth trying those.
 

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I run 215/45-17's on my CS, 40mm lowered, no probs except signs of occasional inner arch scuffing on full lock.

This was the size recommended by Trent. It may also be cheaper than 225/45-17, which is not so common.
 

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Originally posted by Mark E:
[qb]It may also be cheaper than 225/45-17, which is not so common. [/qb][/b]
I'll certainly be comparing prices before I buy. If they're not too much more expensive, I might try the 225s first. If they rub a bit, I'll go down to 215s next time.
 

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Discussion Starter · #15 ·
ohps - yes your all corect, i read it wrong, they are indeed 205/60/15

What im trying to achive is extra width for traction and lower profile for handling.
Without fouling the arches.

so 225 will fit ok? Thanks Scaero owner.

just a question of 16" or 17"

Thanks for your help and sorry for misleading info

Damian
 

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My 91' carlsson is on 7+17 's and I am running on 215/45/17 tyres as advised by a couple of specialists and they are spot on except a slight scuff on a right hand lock,however not being content with this I am currently looking into 18's but for road use only not the track.
 

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I agree Bill; I've been offered a set of 18's in response to my classfied ad but I've said no. Personally I don't want 18's for normal road use, they'd be way too harsh riding and would be too vulnerable to pothole damage.

However, on the track they'd allow you to run an ultra firm responsive set-up. Unfortunately I wouldn't be allowed to "clutter" up my old mans garage with a spare set of rims.
 
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