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Discussion Starter · #1 ·
So I've got a set of 9" wheels I'm planning on running in autox and I'm looking at tires for it - right now I'm debating on whether I should run a 265/35 on that or not

my question is if that is too wide for a 9" wheel or not? from what I've found online it looks like they consider a 265 as the maximum width you can run, so I'm not sure if I'm sacrificing performance by running that wide? My brain tells me that a wider contact patch is better, but I don't know if there are any unforeseen variables I don't know about...I'm still relatively new to trying different kinds of tires, so I wanted to pose the question here and see if the consensus is to go 265 or if I should just stick with a 255?

planning on running Bridgestone RE-71Rs
 

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So I've got a set of 9" wheels I'm planning on running in autox and I'm looking at tires for it - right now I'm debating on whether I should run a 265/35 on that or not

my question is if that is too wide for a 9" wheel or not? from what I've found online it looks like they consider a 265 as the maximum width you can run, so I'm not sure if I'm sacrificing performance by running that wide? My brain tells me that a wider contact patch is better, but I don't know if there are any unforeseen variables I don't know about...I'm still relatively new to trying different kinds of tires, so I wanted to pose the question here and see if the consensus is to go 265 or if I should just stick with a 255?

planning on running Bridgestone RE-71Rs
Correct me if I'm wrong, but wouldn't you be like "disqualified" if you're not running wheels that are the same width as stock for auto-x? Not sure what that even means, have just seen it on these forums. This will be the first car I auto-x as well, and I have some 18x9 TE37s coming my way, but I thought I saw that you have to run the same width wheel as stock. Not sure if that means you'll still be able to run and you're time just not count? Or if they won't let you run?

Either way, I've also read that having a little bit of stretch on the sidewall is actually good for stiffening up the sidewall, improving feedback. It also increases the contact patch from what I've read. I'm gonna start off by running 235/40 on my 9' wheels and see how I like it, and also make sure there's no rubbing. Then, I might go up to like 245 or 255 tops.
 

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Discussion Starter · #3 ·
Correct me if I'm wrong, but wouldn't you be like "disqualified" if you're not running wheels that are the same width as stock for auto-x? Not sure what that even means, have just seen it on these forums. This will be the first car I auto-x as well, and I have some 18x9 TE37s coming my way, but I thought I saw that you have to run the same width wheel as stock. Not sure if that means you'll still be able to run and you're time just not count? Or if they won't let you run?

Either way, I've also read that having a little bit of stretch on the sidewall is actually good for stiffening up the sidewall, improving feedback. It also increases the contact patch from what I've read. I'm gonna start off by running 235/40 on my 9' wheels and see how I like it, and also make sure there's no rubbing. Then, I might go up to like 245 or 255 tops.
that is true for a lot of classes but I run in street mod so it's not as much of a concern - also I'm really not worried about competing too much in autox, so if they don't like it I'll just run as fun and not compete...I'm moreso just enjoying the learning I'm getting from it haha
 
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There really are 2 questions 1) Would they do what you want?, 2) Would they fit?

A 265 on a 9" rim is the minimum rim size and will slightly pinch the tire....which means you may not get the full benefit your seeking of a wider foot print. A 255 would be a better match, or svn a 245 where you would have a slight stretch.

If you step down to a 18" x9" rim and run a 265 35 18 tire you would probably need a 38mm or possibly 35mm offset for inner clearance but you'd be protruding almost 1" beyond the stock outer tire location...which means you have tire poke beyond the fender wells by at least 1/2". You might also run into front inner liner contact with the combination of wheel offset, tire size and rim width when turning the wheels under suspension loading.
 

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Discussion Starter · #5 ·
There really are 2 questions 1) Would they do what you want?, 2) Would they fit?

A 265 on a 9" rim is the minimum rim size and will slightly pinch the tire....which means you may not get the full benefit your seeking of a wider foot print. A 255 would be a better match, or svn a 245 where you would have a slight stretch.

If you step down to a 18" x9" rim and run a 265 35 18 tire you would probably need a 38mm or possibly 35mm offset for inner clearance but you'd be protruding almost 1" beyond the stock outer tire location...which means you have tire poke beyond the fender wells by at least 1/2". You might also run into front inner liner contact with the combination of wheel offset, tire size and rim width when turning the wheels under suspension loading.
that is excellent information and exactly what I was concerned I was missing - I wasn't sure if running a 265 on a 9" wheel would actually have the opposite effect to what I was looking for

for the wheels I've got a 42mm offset so running the calculators online it looks like 265 would probably not fit as well as I initially thought, and on second thought here I'm actually considering that maybe a 245 would be the better fit than even a 255...hmmmm....
 

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The great thing about a 245 is you can run a 245x40x18. There a lot of different tire choices and these are very common....therefore less $$$. A good 245 on either a 9" or 8.5" rim would be a great choice.....and lighter weight than the bigger tire sizes. A 245x40x18 on an 8.5" rim with either a 45 or 40mm offset would fit nicely within the limitations of the RS fenders/suspension, IMO.
 

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265/30/19 fits on the mountune 8.5" wide. 9" even better. 265/35 will be too big.

For autox it should be faster but on the track you'll be slower on the long straights.

People squeeze bigger than rec tires for wheel width all the time for autox. If it's within the tire spec it'll fit easy with negligible pinch.

Hell someone fit 265s on an 8" wide 18.


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Thinking you could probably only get a way with 30 not 35 but you won't know unless you try. After going 265/30 without a problem I find myself wondering if i couldn't have squeezed in a 275.
 

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OP are you talking a 19 or 18 inch wheel? (I'm assuming 18?) That makes a big difference in your questions.
 

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Discussion Starter · #10 ·
OP are you talking a 19 or 18 inch wheel? (I'm assuming 18?) That makes a big difference in your questions.
sorry missed that in my original post - 18" wheel

I only intend to use these tires for autox and daily driving, no track usage as I've got a set of wheels I intend to use only at the track already
 

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Discussion Starter · #11 ·
The great thing about a 245 is you can run a 245x40x18. There a lot of different tire choices and these are very common....therefore less $$$. A good 245 on either a 9" or 8.5" rim would be a great choice.....and lighter weight than the bigger tire sizes. A 245x40x18 on an 8.5" rim with either a 45 or 40mm offset would fit nicely within the limitations of the RS fenders/suspension, IMO.
that is the exact setup I'm running on my track wheels (8" 245x40x18) and it definitely fits nicely - just seems odd to me to run the same tire on a wider rim as it feels like I'm not taking advantage of the extra width? I'm wondering if maybe a 255x35x18 would be the happy middle ground for me
 

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If you want a good daily plus autox I'd recommend 245x40x18 Bridgestone Re11 or RE11 (if you can find them). They have very good grip but also perform well in mixed weather conditions and much lower nvh than Re71. If you want more autox capabilities go to Re71 if willing to tradeoff DD charateristics. Remember none of these tires are suppose to be used under 40 deg F.
 

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If you want a good daily plus autox I'd recommend 245x40x18 Bridgestone Re11 or RE11 (if you can find them). They have very good grip but also perform well in mixed weather conditions and much lower nvh than Re71. If you want more autox capabilities go to Re71 if willing to tradeoff DD charateristics. Remember none of these tires are suppose to be used under 40 deg F.
Why a 245? If he's going to be autox on them might as well get the 265s. They will fit fine.


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I'm not a fan of min rim size for a tire when I'm trying to get max grip/footprint. I prefer a stiff tire shoulder from a larger rim vs tire width...it's a personal driving preferance. A 265 is heavier but you're right it has more static footprint...but as a dual use DD/autox I'd prefer the 245 or possibly 255.
 

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265 isn't too wide for a 9" wheel. Well within spec.

1993-2002 Camaro's and Firebirds came with 275/40/17" on 17x9" rims.

I'm running a set on my TransAm.
 
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Discussion Starter · #16 ·
If you want a good daily plus autox I'd recommend 245x40x18 Bridgestone Re11 or RE11 (if you can find them). They have very good grip but also perform well in mixed weather conditions and much lower nvh than Re71. If you want more autox capabilities go to Re71 if willing to tradeoff DD charateristics. Remember none of these tires are suppose to be used under 40 deg F.
yeah I live in California where if it gets to 50 degrees out people freak out and throw on the thickest of jackets haha...plus I don't have any commute so I don't mind a more performance minded tire for my DD

I'm thinking I've settled on the 255 - the 265 will definitely fit the wheel but it looks like it might stick out from the fender a bit, and I've got a lot of pictures with how much my car squats in turns so I'd be worried it'd wear on the fender when auto-xing...I think the 255 is definitely a nice tradeoff to take advantage of the wider wheel, get a decent sidewall stiffness, and still utilize more footprint

thanks for all the input guys!
 

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It'll be fine. It's not a safety concern and 9" is within width range for a 265 section tire. I wouldn't get too caught up on which wheel or tire to run. As a novice, you're going to get beaten by experience, not equipment.

Buy what you like and realize that tires are a wear item.You'll be replacing them often in autocross.

donour
 
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