8 and 9j tyre size

*P3nfold*

*P3nfold*

Registered User
Joined
Jun 22, 2012
Messages
366
Reaction score
15
Points
18
Location
Billingshurst
Hi all,

I currently have 225/40/18 on the current 8j's on the fronts and dont really want the stretched look on the rears to match, I like having solid tyre walls.....

Could anyone recommend a tyre size what would match the fronts on 9j's please?
 
jojo said:
255/35/18 is nearer 225/40/18 for rolling radius.
Click to expand...

True, but he said he wanted something that matched the fronts so I figured he'd want the same. :p They're wider not bigger diameter.
 
lovemelongtime said:
Cheers fella,

So thats

225/40/18 Fronts
245/40/18 Rears

Funny enough I was looking at a tyre size calculator at 235/40/18 for the rears, do you think there will be stretch?
Click to expand...

A little by comparison to the fronts, but it won't be mental.. Like my 225/40 on 9.5J :)
 
Very important to get the rolling radius front and rear close as possible. Get it wrong and the ESP throws a fit and the haldex clutches eat themselves.

Routledge, profile is a percentage of the width so 245/40 has larger radius than 225/40.
 
BENJAMIN said:
Very important to get the rolling radius front and rear close as possible. Get it wrong and the ESP throws a fit and the haldex clutches eat themselves.

Routledge, profile is a percentage of the width so 245/40 has larger radius than 225/40.
Click to expand...

Thanks you. :icon_thumright:
 
Whoops, I thought it was a percentage of overall diameter. So, what you're saying is that me running 225/40/18 all round with staggered fitment wheels 8.5 and 9.5 will mean my ESP will go mental and cost me loads?

I've not noticed any change :/
 
Routledge said:
Whoops, I thought it was a percentage of overall diameter. So, what you're saying is that me running 225/40/18 all round with staggered fitment wheels 8.5 and 9.5 will mean my ESP will go mental and cost me loads?

I've not noticed any change :/
Click to expand...

Same size tyre so difference is minimal. There is a tolerance built in to allow for say, 2 new tyres at the front and 2 worn out tyres at the back. I'd imagine yours would fall into this allowance as its so minimal.

You can't however run 225 40's at the front and 245 40's at the back.
 
245s fit a 9 quite well. I run them all round but 245/40/17:

wheelson1.jpg
 
BENJAMIN said:
Very important to get the rolling radius front and rear close as possible. Get it wrong and the ESP throws a fit and the haldex clutches eat themselves.

Routledge, profile is a percentage of the width so 245/40 has larger radius than 225/40.
Click to expand...

Cheers Ben.
 
Do you think the s3 will look ok with 9j 255/35/18 on the rears with 8j 225/40/18?
 
BENJAMIN said:
Same size tyre so difference is minimal. There is a tolerance built in to allow for say, 2 new tyres at the front and 2 worn out tyres at the back. I'd imagine yours would fall into this allowance as its so minimal.

You can't however run 225 40's at the front and 245 40's at the back.
Click to expand...

Fair play. I'll go back to minding my own business then ;)

EDIT: I'm due to have you fix something actually.. So I expect I'll be calling you soon.
 
jojo said:
It will look fine, but squeezing 255s under the rear arches require the correct offset. What you could do is use 235/40R18 all round I guess?
Click to expand...

ET on the rims are 35, I have a rear adjustable tie arm as well so I guess I can play round with that?

Not sure on the 235/40/18, I dont really want any stretch on the 9s.

humm this gets you thinking lol.
 
lovemelongtime said:
ET on the rims are 35, I have a rear adjustable tie arm as well so I guess I can play round with that?

Not sure on the 235/40/18, I dont really want any stretch on the 9s.

humm this gets you thinking lol.
Click to expand...

235 on a 9 will be fine mate. 255 is a little large for the arches IMO
 
Im running 225 on 9.5j and it looks fine
 
Yeah I reckon 255 would be ok on the rear but it'd be pretty crucial to get the offset spot on. I have a bit of space with 245s.
 
jojo said:
He doesn't want stretch, that looks stretched! Lol
Click to expand...

Thanks milli

jojo said:
And so he did, I shall crawl back under my rock. Lol
Click to expand...

Lol Cheers jojo

Thats too much stretch for me. I've been there and done the stretch tyres with sub 300 bhp, did not feel safe to me. So tyre on the tarmac is for winners and solid tyre walls.

So looking at the thread, so 235/40 on the 9s only will be fine? 1.26% is the difference between tyre sizes, so that equals 8mm diameter change.
 
old thread now but im stuck! just bought new wheels...

8.5j and 9.5j.... tires already on them 225/40 all round...

clearly back has stretch as photo above...

this setup ok on my s3 radius ok?

i dont know how you work it out :s any idea what tire size i could get for the rear 9.5j for a little LESS stretch!? bit much for my liking! :/ thanks in advance!!!! :)
 
235s or 245s are what you want really on a 9 or 9.5 unless you want scene points for "sik stretch". I'm getting new tyres on Monday (AD08Rs) and going for 255/40/17 rear and 245/40/17 front.

This is a good tool to compare sizes and rolling radius differences:
Visual Tyre Size Calculator | Kouki Tech
I don't pay too much attention to the visual representation of the actual tyre size as it's a little off.
 
limbo118118 said:
old thread now but im stuck! just bought new wheels...

8.5j and 9.5j.... tires already on them 225/40 all round...

clearly back has stretch as photo above...

this setup ok on my s3 radius ok?

i dont know how you work it out :s any idea what tire size i could get for the rear 9.5j for a little LESS stretch!? bit much for my liking! :/ thanks in advance!!!! :)
Click to expand...

If the tyre sizes are correct front and rear, then the rolling radius should be correct irrespective of stretch on the sidewalls?
 
jojo said:
If the tyre sizes are correct front and rear, then the rolling radius should be correct irrespective of stretch on the sidewalls?
Click to expand...

Tryed reading up loads on if tonight but iv can sit the wheels next too each other and the front sits higher and it has less stretch so would of thought that would of made a difference?
 
limbo118118 said:
Tryed reading up loads on if tonight but iv can sit the wheels next too each other and the front sits higher and it has less stretch so would of thought that would of made a difference?
Click to expand...

Fair enough, I walkways thought the stretch was in the sidewalls, it cam compress the tread area aswell to reduce the rolling radius. Another reason for me to never go with stretched tyres, as they are clearly not designed by the manufacturer to be used in such a form.

Don't get me wrong, I have nothing against stretched tyres, but I just think I prefer my car, with it's 270odd horses to be unleashed on proper fitted tyres.
 
You must log in or register to reply here.

Similar threads

A
tyre size and spec
Replies
2
Views
837
superkarl
superkarl
S
Tyre Size On 8.5 & 9.5j
Replies
2
Views
5K
Sam_
Sam_
s3james
Tyre size help and fitment
Replies
12
Views
4K
Tj 0785
Tj 0785
kelk11
Tyre size
Replies
2
Views
616
kelk11
kelk11
MURRAYS444
Tyre Size
Replies
7
Views
1K
superkarl
superkarl
Top
Back