205/50 on 15x8 - Dealers refuse to fit this?

Dweezle · Postby **Dweezle** » Wed Oct 26, 2016 9:09 am

What stretch??

I found a 205 on a 8 is quicker than a 205 on a 7.

A 225 is quicker on a 8 then a 205.

And a 225 is quicker on a 9 than a 8.

Sent from my SM-N9005 using Tapatalk

RS2000 · Postby **RS2000** » Wed Oct 26, 2016 9:20 am

I think we all know 205mm = 8". But tyre width is not the same thing as the distance across the beads.

RS2000 · Postby **RS2000** » Wed Oct 26, 2016 10:57 am

Dweezle wrote: A 225 is quicker on a 8 then a 205.

That confirms what the motorsport tyre people have been telling me. They say the 225 on 8" are quicker than 205 on 8", not just because they are wider, but also because there is less stretch & more give in the side walls. However 205's cost less & there is more choice.
Does anyone know if some dealers won't fit 205 on 8" road use rims because its illegal?
Cheers

StanTheMan · Postby **StanTheMan** » Wed Oct 26, 2016 11:42 am

RS2000 wrote:
Does anyone know if some dealers won't fit 205 on 8" road use rims because its illegal?
Cheers

Yes there is plenty of those around here on the Northern Beaches In Sydney. Its all about being scared to face litigation. Unfortunately its just a reality of life. Australia has higher litigation per capita than California.

Think about this.
I'm a Mountain Biker. At a local MTB trial, you have to cross a busy 2 lane road rated at 80km/h. To prevent people from crossing the road & potentially getting run over, they are considering putting up a fence so you can't enter a different track on the other side of the road. :roll:

Its the sad truth.

rascal · Postby **rascal** » Wed Oct 26, 2016 1:41 pm

RS2000 wrote:I'm told by very experienced motorsport people, that the extra stretch of 205/50 on 8" rims will reduce grip compared to them on 7". Likewise compared to 225 on 8".

Very experienced doesn't always translate into very knowledgeable....

In my experience, (real world usage) I've found 205s on 8s were quicker than 205s on 7s..

And sadly you find more and more dealers who are more concerned about being sued than providing good service.
I used to take my rims in loose and was never knocked back fitting 205s to 8s.

RS2000 · Postby **RS2000** » Wed Oct 26, 2016 3:35 pm

Fair enough rascal.
I have 8" rims, & was more concerned with 205/50/15 verses 225/45/15. I'm buying the 225's.

captaincabinets · Postby **captaincabinets** » Wed Oct 26, 2016 9:39 pm

smy0003 wrote:15x7 isn't a bad option (considering you haven't bought wheels yet?), they will be legal, lighter and unless you're a track monster there won't be any noticeable performance benefit from the 15x8s.

Logically, agree with you 100%. Tyres would be easier to get too and will be cheaper. But logic goes out the window when I look at these:

They're only ~$40 more for the 8", and the weight difference is minimal. I've pretty much talked myself into them.

plohl · Postby **plohl** » Thu Oct 27, 2016 7:58 am

I have found no difference in times with 205/50 ao50's vs 225/50 ao50's on 15x8s... If there's any benefit, I'm not good enough to find it. Which being honest, is probably the same as 98% of the people on this forum.

I have also been fitting 205/50s to my car 15x8s for the last 4 years, never had an issue - rims always go in by themselves, but I don't think taking the car in would have stopped them

Sent from my SM-N9005 using Tapatalk

rascal · Postby **rascal** » Thu Oct 27, 2016 8:59 am

plohl wrote:I have found no difference in times with 205/50 ao50's vs 225/50 ao50's on 15x8s... If there's any benefit, I'm not good enough to find it.

What type of tracks did you notice this? ie tight and twisty or fast and open.
The extra cornering power of the wider tyre is offset by a reduction in straight line speed, due to weight, drag, and potential gearing issues.

So you should notice the gains with the wider tyres on a tight and twisty track, and much less so on a fast open track, where you may actually be slower with the wider tyres, even if you do have extra cornering power..

plohl · Postby **plohl** » Thu Oct 27, 2016 9:46 am

Lakeside - has a pretty high average speed i suppose.

MattR · Postby **MattR** » Thu Oct 27, 2016 6:21 pm

As Pohl said, only about three people on this forum would notice any speed difference between a 205 or a 225 tyre on an 8" rim on the track.

Sad thing nowadays is people are putting skinny tyres on fat rims, back in my day it was trying to get a 245 tyre to fit on a 7 inch rim or a 295 onto an eight inch rim, with baggy sidewalls and all.

Oh, and as everyone has said, find another tyre shop to buy the tyres from and fit them. That size should be no worries to fit on an 8.

Earlysport · Postby **Earlysport** » Sat Nov 12, 2016 4:30 pm

RS2000 wrote:I'm told by very experienced motorsport people, that the extra stretch of 205/50 on 8" rims will reduce grip compared to them on 7". Likewise compared to 225 on 8".

Your Motorsport friends are Incorrect. Plenty of actual test results on miataturbo.com

rhyde · Postby **rhyde** » Sun Nov 13, 2016 3:02 am

haha this is too funny
i started a thread on the very same problem.
frekn did my head in
three dealers would not fit 215s 45 17s on my nc mx5

went to bob jane in maribrynong melb, he said he didnt give a crap what size i put on

captaincabinets · Postby **captaincabinets** » Sun Nov 13, 2016 9:35 am

Haha I am making assumptions but Maribyrnong sounds like a suburb where people would be chilled.

Lokiel · Postby **Lokiel** » Sun Nov 13, 2016 10:21 am

Saw an over-the-top tyre stretch on an S-15 yesterday, not sure how they even sealed properly, I could see the entire lip of the rim clearly protruding from the tyre (and guard - without the massive tyre stretch there's no way those tyres would have fit under the guard).

With his massive fart can and stretched tyres, it wont be long before he's defected.

Obviously you can always find someone who will agree to fit stretched tyres, no matter how ridiculous/illegal.