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Discussion Starter #1
On my GTR at the moment.
They are Smiths Alloys, wide wheels at the back. The rubber is excellent and wheels have light curbing on a couple of places.





i have the centre caps btw

I'm looking for £500 ono

Faz 079 0406 9525
 

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Discussion Starter #3
Yunis A said:
yeah dont drive the car untill you get a set of matched front and rear wheels, odd size is definately a no no on GTR's
??? they are matched
 

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kirbz said:
its the profile you have to be careful with the gtr not the width i would have thought??
Profile is stated as a relative percentage of tyre width, therefore if your width is different on front compared to rear it's difficult to get the same rolling radius front and back.

So yes, if you can get the *absolute* depth of the tyre profile to be exactly the same on the front and back (assuming wheels are the same radius) then you're ok. But it's neigh on impossible to do this with different width wheels front and back.

For example, 265/35/R18 on the back and 225/35/R18 on the front will give you the same alloy radius but the profile on the rear is 265 x 0.35 and front is 225 x 0.35, giving different profiles and therefore different rolling radius- radiui- radiuses. B0ll0cks - what's the plural of radius??

You can try to reverse engineer the maths and find a tyre that will give you the same absolute profile front and back but I'll bet you 99 times out of a 100 you won't be able to find a tyre that matches your required width/profile combination...
 

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Alloy Widths make no difference, only Tyre widths

A 245 tyre on a 18x8.5 or a 18x9.5 is still 245 wide.

glad they sold matey!
 

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Tyre widths make no difference, it's all about the rolling radius. As long as two different size tyres have very similar rolling radius (as lets face it, new tyres on the front and the same size old tyres on the rear will only be similar, not identicle) then they'll be fine.

It's a little odd how many Skyline owners are happy to use random plug in ECUs and risk their expensive engines. But they get all protective of their transfer boxes (which can be bought for £100 second hand) when the subject of different size front and rear tyres is mentioned...
 

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I wud of thought the most important aspect is the profile, not the width. i.e
245.35.18 on the front with 255.30.18 on the rear wud of caused some damage over time as the rears are trying to turn more revolutions than the front as it's 10mm less in diameter.

If the rear tyre matched the front with a 35mm profile, being 10mm wider on the same diameter rim however, one wud think no wear / damage at all.
 

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neeltec said:
I wud of thought the most important aspect is the profile, not the width. i.e
245.35.18 on the front with 255.30.18 on the rear wud of caused some damage over time as the rears are trying to turn more revolutions than the front as it's 10mm less in diameter.

If the rear tyre matched the front with a 35mm profile, being 10mm wider on the same diameter rim however, one wud think no wear / damage at all.

It is not in mm. The profile (wall height) of the tyre is a %. So in your two quoted sizes 245.35.18 , the profile is 35% of 245mm and so on. This shows how hard it is to get two different width sizes with the same profile (same tyre wall height). It is near on impossible.

All GTR's, as they are 4wd, need the same rolling radius so as not to confuse the electronics.

Nik
 
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