40's or 45's???

[mixupz]

i recently got 17's for my ibiza mk4 (2004) 1.2 12v tyre fitments are pair of 205/40/17 and 215/40/17 i need new tyres to replace the 215/40/17's ....my mate has two 205/45/17 tyres....if i use this higher profile tyre on the back will it cause me any problems?

[ror100]

As far as I know it's illegal, all 4 tyres must be the same size (not necessarily the same brand or tread pattern though).

[Bell_130]

It'll look daft i reckon. 45s will look overtyred and will look odd if you've got 40s on as well. You've also got the rolling diameter to think about....

[Alan]

As above, it'll look silly, it'll probably rub on your arches especially if you have some weight in the back, it'll make the back end look even higher than it already is, etc.


As far as I know it's illegal, all 4 tyres must be the same size (not necessarily the same brand or tread pattern though).

Tyres should be the same all round, but as long as you stick to one size and tread pattern style on each axle, then it's still legal, unless the size difference is deemed unsafe.

[mixupz]

thanks guys! :) for putting an end to my tight pocket ways :)

[Teutonic_Tamer]

As above, it'll look silly, it'll probably rub on your arches especially if you have some weight in the back, it'll make the back end look even higher than it already is, etc.



Tyres should be the same all round, but as long as you stick to one size and tread pattern style on each axle, then it's still legal, unless the size difference is deemed unsafe.

That is not true.

In an ideal world, all four tyres should be the same make, tread pattern, size and wear. However, front wheel drive cars are notoriously heavy on front tyres, and will wear at about six times the rate of the rears.

It is very strongly recommeded to keep axles matched, ie identical tread paterns and wear on the front axle (or rear axle).

Differences between front and rear axles are perfectly acceptable. For example, BMW, Porsche, Lotus and VX200 are supplied with noticeably wider tyres at the rear, compared to the fronts. Furthermore, many Ferraris are supplied with directional tread patterns on the front axle, and assymetric tread patterns on the rear axle.

[Alan]

Tyres should be the same all round, but as long as you stick to one size and tread pattern style on each axle, then it's still legal, unless the size difference is deemed unsafe.

That is not true.

In an ideal world, all four tyres should be the same make, tread pattern, size and wear. However, front wheel drive cars are notoriously heavy on front tyres, and will wear at about six times the rate of the rears.

It is very strongly recommeded to keep axles matched, ie identical tread paterns and wear on the front axle (or rear axle).
Urm, is it just me or have you just agreed with what you said was not true :rolleyes:


Differences between front and rear axles are perfectly acceptable. For example, BMW, Porsche, Lotus and VX200 are supplied with noticeably wider tyres at the rear, compared to the fronts. Furthermore, many Ferraris are supplied with directional tread patterns on the front axle, and assymetric tread patterns on the rear axle.
No one said they weren't :rolleyes: Having wider tyres on one axle wouldn't be deemed unsafe, having taller tyres might depending on the size difference.

[Teutonic_Tamer]

Urm, is it just me or have you just agreed with what you said was not true :rolleyes:

:noidea: :confused: Hmmm, there are too many questions in that above ^^^ statement ?????


No one said they weren't :rolleyes: Having wider tyres on one axle wouldn't be deemed unsafe, having taller tyres might depending on the size difference.

I was merely trying to clarify the issue, as I thought your post slightly confusing (sorry!). I just think you were confusing the issue between what is "legal" and what is "safe". :bounce:

Regarding the "legal" issue - the law is quite straightforward. Surprisingly, there is NO legal requirement to have the same size tyre, ANYWHERE on the vehicle. Legally, you could have 4 different makes, tread patterns, AND different sizes on all 4 corners - sensible: NO, legal: YES. The only legal requirement regarding different tyres, is if you have a mix of cross-ply, and radial-ply tyres - in that instance, cross-plys must go on the front axle, and raidals must go on the rear. :nerd:

Regarding the "safe" issue. There is technically no such measurement of "safe". If the tyres are unsafe, then it is highly likely they are illegal.

The differences in heights between front and rear axles - again, as there is no specific definition of "safe", then providing they are legal, then you are OK. The fact that they will look utterly stoooopid is down to personal taste (unless it is a modified custom hot-rod).

One crucial issue which hasn't been mentioned, if you have different height tyres between front and rear axles, be that through different sizes, or through general wear - can cause certain problems with certain cars. If you have a four wheel drive car with a viscous coupling as the centre diff (Haldex), then you risk toasting your diff. Also, if you have a car (4wheel drive or 2wheel drive) which has any kind of electronic traction control or stability system, then the different rolling radii will cause havoc with the relevant TC/ESP ECUs.