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I recently bought some 15' XXR 527's which are 8.25" wide, according to Willtheyfit.com (it's a very good site go have a look) I want them to run a 245/40 tyre to keep the stock "stretch" but this tyre size isn't available from what Google tells me! What tyre size do you guys usually run on 8" wide rims? also considering i have an NA so i want it to be as close as possible to stock diameter so I don't have an issue with the speedo

IMPORTANT EDIT***

Hate stretch, hate stance, want this to be for GRIP, i.e. why wanting to run 245's

225/45?/15 hankook rs3. Slightly larger diameter then stock I think being discontinued though I believe.

225 is reasonably had to get, 245 would be impossible short of slicks I would think.

205 is technically illegal on a 8" rim (based on tire manufacturers recommended fitting ranges)


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The only DOT legal tyre in that size is a Hoosier A6/R6. They are basically a slick though and completely unsuited to road driving.

You want Nitto NT01s in 225/45/15.

Awesome, thanks guys, I wanted to go as wide as possible for grip but wanted to check what others run first so i didn't have an unexpected bad time haha

We are running a AD08R 205/50/15 on 6UL 15x8.

Tyre is not stretched that much and doing 12's at Wakefield with a road regod NA6 with 80rwkw, grip is not low.
My brother runs a quicker lap with the 205 vs a 225.

Running a 8" wheel is illegal on a MX5 in NSW anyways so Tyre size will not help that out.


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Most tyre calculators indicate the 205's aren't suited for 8" rims which seems a bit odd given that 8" = 203.2mm.
Does 1.8mm really make a difference?
Given that tyres are made of rubber and do flex, they seem like a perfect fit.

I run 205/50/15 Dunlop Direzza Sport Z1 Star Specs on my DD 6ULs and they fit perfectly with no stretch. The 6UL creator, Emilio, reckons that 205s are perfect for a DD with 8" 6UL rims.

My track tyres are 225/45/15 Toyo R1Rs which are slightly too wide for 6UL 8" rims.


One thing to be wary of though is that tyre sizing seems to be "more of a guideline" than an actual physical standard.
eg. Some manufacturers 205s are wider than others.


Dweezle: The SE came with 7" rims. My understanding is that cars can't go beyond 1" of their OEM rim width. If that's the case, please correct me if I'm wrong, then SEs CAN legally run 8" rims.

Lokiel wrote:Most tyre calculators indicate the 205's aren't suited for 8" rims which seems a bit odd given that 8" = 203.2mm.
Does 1.8mm really make a difference?

205 is the widest point of the tyre. normally the sidewall.

the bead is about 15mm inwards, so 30mm skinnier than the 205. and the should is also skinner than 205.

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205/50 is a larger rolling diameter than 225/45 so you'll find that the increase in width but loses in rolling diamter for 225s dont mean much grip increase over 205s.

Lokiel wrote:Dweezle: The SE came with 7" rims. My understanding is that cars can't go beyond 1" of their OEM rim width. If that's the case, please correct me if I'm wrong, then SEs CAN legally run 8" rims.

Ahhh my bad
I forgot about the SE.

My understanding is the same as yours with 1".



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what offset are they? if they are zero the only tyres you can run are 195's LOL. maybe 205's if you pull the hell out of the guards and are low with camber.

Lokiel wrote:Most tyre calculators indicate the 205's aren't suited for 8" rims which seems a bit odd given that 8" = 203.2mm.
Does 1.8mm really make a difference?
Given that tyres are made of rubber and do flex, they seem like a perfect fit.

I run 205/50/15 Dunlop Direzza Sport Z1 Star Specs on my DD 6ULs and they fit perfectly with no stretch. The 6UL creator, Emilio, reckons that 205s are perfect for a DD with 8" 6UL rims.

My track tyres are 225/45/15 Toyo R1Rs which are slightly too wide for 6UL 8" rims.


One thing to be wary of though is that tyre sizing seems to be "more of a guideline" than an actual physical standard.
eg. Some manufacturers 205s are wider than others.


Dweezle: The SE came with 7" rims. My understanding is that cars can't go beyond 1" of their OEM rim width. If that's the case, please correct me if I'm wrong, then SEs CAN legally run 8" rims.

What does the SE tyre placard say? I understand that is the baseline for what is permitted.

As far as sizing is concerned, the dealer stated categorically that my 205/50 x 15 R-specs should not be used on rims wider than 7in. Tyre design is therefore a consideration.

greenMachine wrote:As far as sizing is concerned, the dealer stated categorically that my 205/50 x 15 R-specs should not be used on rims wider than 7in. Tyre design is therefore a consideration.

Maybe by the letter of the law on road, but on track (where Rspecs are for) the 8" rim is quickest for 205s

If we all listened to the dealer we'd all be tracking 14x6s and 185s....

+1 rascal

Track testing has proven to 949racing that for their 6ULs:
* 205s are quickest on 8" rims
* 225s are quickest on 9" rims

Given that strict tyre widths are not actually enforced despite their grading, enforcing generic tyre/rim fitting "rules" seems pointless unless they're based an actual tyre+rim measurements.

Thanks for the info guys, I believe the laws must be different in QLD because I thought I saw people saying that in QLD you are aloud to change wheel width by 2inches, can anyone confirm this or not?

Also I am running XXR 527's which are 8.25" wide, considering these are not my track rims and I want to get a set of 6ul's for track would it be best to run 205's or go up to 225's? I know that both these options will then require flares to get the wheel to fit in the guards. So in short I don't want stretched tyres and I don't need the best wheels for track, these are my daily wheels which will see a little track time until I have 6ul's.

Also I have an NA but it's a Japanese import so It doesn't have a tyre placard so I've been told its "legal" to run any wheel size I want

So zero offset / "ET 0" ?


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emily_mx5 wrote:So zero offset / "ET 0" ?


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Yep haha, 15x8.25 0 offset, aggressive as