Tyre sizing for 15x8's

siren676 · Post by **siren676** » Mon Jul 02, 2012 7:24 pm

Im planning on fitting my og oldskool wheels (15x8 +25 offset) soon and want to stick some newer tyres on them.
They currently have 195/45-15's on them but got told they had too much stretch when i went for a cert with them on my starlet.

What size tyres should i go for? I assume 205/50-15 would be about right for the rolling radius?
I guess clearance shouldnt be an issue as ive seen some cars with 0 offset and they are very flush.

Bwarp · Post by **Bwarp** » Mon Jul 02, 2012 8:05 pm

think to get cert on an 8inch wheel you need to run 225's.....

http://lvvta.org.nz/documents/infosheet ... _Guide.pdf

that's the LVVTA info sheet

evel · Post by **evel** » Mon Jul 02, 2012 8:09 pm

215-245 is the width they like on 8 inch rims, unless the tire has been deemed safe to run on said width. I believe theres is a set of nankang tires that are 195's that you can use on 8 inch rims

siren676 · Post by **siren676** » Mon Jul 02, 2012 8:18 pm

Would 225's even fit in the guards?

Using a tyre size calculator it looks like i'd need 225/45-15's to keep the rolling radius. This could be expensive as i think that size is rather hard to find

siren676 · Post by **siren676** » Mon Jul 02, 2012 8:19 pm

Im not planning on doing anything which will require certing for a while so i guess i could get away with some skinnier tyres?

evel · Post by **evel** » Mon Jul 02, 2012 9:25 pm

Rolling radius isnt a biggie, your spedo will only be out by a few k's. well yeah if your not going to go for a cert for a while then dont stress. I dont know what the cops are like with stretched tires as it still relatively new

Mr. Shine · Post by **Mr. Shine** » Mon Jul 02, 2012 9:29 pm

Tyre width is not a matter of requiring certification, rather appropriate tyre width does not require certification. For WoF purposes, changes to wheel width and tyre size need to meet the standards set out for not requiring certification, namely that the tyres are an appropriate selection for rim width.

harlansmart · Post by **harlansmart** » Mon Jul 02, 2012 9:44 pm

... about to find out, Vader miata I have is currently being equipped with 225/50 on 8 x 15 up in Northcote with wheel guru Zac at his tyre shop - hoping to get a gauge on the fit this week.

siren676 wrote:Would 225's even fit in the guards?

... fwiw the 27mm spacers are off and on Trademe for $1 and now on the 6.5 x 15 w/ the semi slicks he looks woefully underdone... yesterday top of the Waitaks.

authentic · Post by **authentic** » Mon Jul 02, 2012 9:54 pm

Mr. Shine wrote:Tyre width is not a matter of requiring certification, rather appropriate tyre width does not require certification. For WoF purposes, changes to wheel width and tyre size need to meet the standards set out for not requiring certification, namely that the tyres are an appropriate selection for rim width.

Are you able to get certed for stretched tires outside of the appropriate standards at all? I really want to run 195s on an 8 inch wide wheel, but I want to do it legit.

siren676 · Post by **siren676** » Mon Jul 02, 2012 9:56 pm

harlansmart wrote:... about to find out, Vader miata I have is currently being equipped with 225/50 on 8 x 15 up in Northcote with wheel guru Zac at his tyre shop - hoping to get a gauge on the fit this week.

Awesome, let me know how you get on.

If they dont fit easily ill just have to find some slightly skinnier tyres which are allowed my the manufacturer and keep the tyre chart in the glove box for wofs or on the off chance a police check

siren676 · Post by **siren676** » Mon Jul 02, 2012 9:59 pm

authentic wrote:
Mr. Shine wrote:Tyre width is not a matter of requiring certification, rather appropriate tyre width does not require certification. For WoF purposes, changes to wheel width and tyre size need to meet the standards set out for not requiring certification, namely that the tyres are an appropriate selection for rim width.
Are you able to get certed for stretched tires outside of the appropriate standards at all? I really want to run 195s on an 8 inch wide wheel, but I want to do it legit.

You can get stretched tyres certed, you just have to find the manufacturers chart which says they are allowed on your width rim and submit it when you go for a cert

punkoutnz · Post by **punkoutnz** » Mon Jul 02, 2012 9:59 pm

If they do fit (pretty sure they will) then you'd be best off with the wider tyres. Running a stretched tyre makes the car damn twitchy, especially at the back end grip side of things! The more the stretch, the worse it is. Function over form people!

siren676 · Post by **siren676** » Mon Jul 02, 2012 10:02 pm

anything will be better than the near plastic 185's its currently got on it

harlansmart · Post by **harlansmart** » Tue Jul 03, 2012 1:38 pm

Anyone here actually running 225/50 on their NA? I was pondering whether to run 205/50 or even go for a full on stretched look with 195/50s and go really low or go for moar grip and forget the whole 'looks' thing and run the big grippy rubber which will likely mean I am not able to run real low...

225/50 will likely work ok in the rear but maybe a bit more tough to fit up front, could always stagger I s'pose.

Pics of 225/50 would be awesome from someone running them here locally?

siren676 wrote:Awesome, let me know how you get on.

punkoutnz · Post by **punkoutnz** » Tue Jul 03, 2012 3:21 pm

http://www.mx5forum.co.nz/ads_item.php?id=409

Flared guards but here's Keith Jone's ad for his wheels with 225 tyres on. Could ask him if they would fit in standard guards.

harlansmart · Post by **harlansmart** » Tue Jul 03, 2012 3:27 pm

Yeah cheers for that big guy, have been to Keith's quite a few times this year to glean beta (and generally stop him working on his race car) but unfortunately there's actually quite a difference between 45 and 50 profiles in real life (more than you think)... actually semi-considered his rims but I wanted only genuine RAYS or WORK rims for pure froth value.

Small short flares can be really cool though, 100% agreed:)

punkoutnz wrote:http://www.mx5forum.co.nz/ads_item.php?id=409

Flared guards but here's Keith Jone's ad for his wheels with 225 tyres on. Could ask him if they would fit in standard guards.

Post by **jif** » Tue Jul 03, 2012 4:29 pm

225/50x15 TE37 et43 on the front ... no probs, apart from slightly rubbing the intercooler inlet at full lock. Looked perfect !

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harlansmart · Post by **harlansmart** » Tue Jul 03, 2012 4:47 pm

Pics Pics Pics

jif wrote:225/50x15 TE37 et43 on the front ... no probs, apart from slightly rubbing the intercooler inlet at full lock. Looked perfect !

[Posted via external email]

evel · Post by **evel** » Tue Jul 03, 2012 8:38 pm

punkoutnz wrote:Function over form people!

Post by **jif** » Tue Jul 03, 2012 9:12 pm

oops.. that should be 205/50... and they were 15x7. Its been a while...

https://plus.google.com/u/0/photos/1010 ... 2764395233

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harlansmart · Post by **harlansmart** » Wed Jul 04, 2012 1:01 pm

No sweat - am off in 10 mins to grab my WORK footwear so we will all know how they fit pretty soon

Ok, so I am back, 2low2c again helped me out (good guy AAAA++++) and they only touch the fitting which holds the lower airdam to the bottom of the bumper - till I take this off and adjust it I cannot put the car back to it's normal height, so it's up the air a bit... here you go:

Genuine WORK Forged Monoblocks in 8x15" 25p, TOYO PROXES T1-R in 225/50

...much moar low is needed, coming soon....

There is quite a bit of tire... it's too soon to say how just exactly how much less grip I have than w/ the semi's but it feels like the the Toyo PROXES T1-R's are not going to offer anything like the grip... I got them hot and I can slide much much more easily now which is fun I guess but slow... am starting to think 225/50 semis are the way, light cars, you still get 5,000kms from grippy tires so...

For reference if anyone cares... standard vs 6.5x15 195/50 semis vs 8x15 225/50 T1-R

Mad Kiwi · Post by **Mad Kiwi** » Wed Jul 04, 2012 10:39 pm

So that skinny ass, 195 semi (r888?) has way more grip than the T1r in a 225?

Imagine what a 225 Semi would give then.....

Maybe there is hope for my laptimes yet....(195x15 T1r's).....

Kieran · Post by **Kieran** » Thu Jul 05, 2012 9:40 am

I thought the genuine Work Meisters were 3 piece?

Nevermind just looked they are 2 Piece

Why such a high offset might I ask?
I just like the huge dish that you can get with those wheels

harlansmart · Post by **harlansmart** » Thu Jul 05, 2012 1:18 pm

Meisters can be in 1, 2 & 3pc... I don't know what you mean by 'hi offset' as these particular rims, that you see on the vader car are +25p

Kieran wrote:I thought the genuine Work Meisters were 3 piece?

Nevermind just looked they are 2 Piece

Why such a high offset might I ask?

Angreal · Post by **Angreal** » Thu Jul 05, 2012 1:52 pm

15x7 seems more convenient than 15x8 in terms of tyre sizes for a road car (not to mention cheaper?)... I guess I'm being too practical here