Michelin PS3 tyres - Speed/Load Rating Question

[DickSkruttock]

I'm looking at buying four PS3s for my S3.

The size I need is 225 45 17, but from what I've seen there are two typres of speed /load ratings - 91Y and 94W for this size.

As I'm no tyre guru, could someone explain the pros and cons of both? It is mainly used for commuting, with the odd bit of spirited driving.

Many thanks.

[E30M3SE]

Y is speed rated to 186mph
W is speed rated to 168mph

91 load index 615Kg's
94 load index 670kg's

replace like with like.

[DickSkruttock]

E30M3SE said:

Y is speed raed to 186mph
M is speed rated to 168mph

91 load index 615Kg's
94 load index 670kg's

replace like with like.

Thanks for the response.

Would the difference in the 91 and 94 rating be noticeable - unless pressing on?

[mmm-five]

DickSkruttock said:

Would the difference in the 91 and 94 rating be noticeable - unless pressing on?

It's not whether it's noticeable or not - if your S3 requires 94 rated tyres and you put on 91 then there may be liability issues in the event of an accident. In your case a W/Y/Z should be fine.

Check what you have on currently or what the handbook says, and fit the new ones that match/exceed the spec you need.

[deveng]

it requires 91Y

Many tyre manufacturers are now changing to 91W on their latest tyres but essentially WYZ are all interchangable providing the load index is correct.

[JR]

deveng said:

it requires 91Y

Many tyre manufacturers are now changing to 91W on their latest tyres but essentially WYZ are all interchangable providing the load index is correct.

NB that W and Y are sub divisions of Z. If you have a W or Y tyre have a read of the tyre wall.

[DickSkruttock]

mmm-five said:

It's not whether it's noticeable or not - if your S3 requires 94 rated tyres and you put on 91 then there may be liability issues in the event of an accident. In your case a W/Y/Z should be fine.

Check what you have on currently or what the handbook says, and fit the new ones that match/exceed the spec you need.

I have Conti Contacts on at the moment - 91W - but they're worn and making a failed wheel bearing noise, which is a commonish thing with Conti Contacts on S3s and S4s - they 'square up'.

This is why I'd prefer a higher load rating.

[mmm-five]

DickSkruttock said:

I have Conti Contacts on at the moment - 91W - but they're worn and making a failed wheel bearing noise, which is a commonish thing with Conti Contacts on S3s and S4s - they 'square up'.

This is why I'd prefer a higher load rating.

Well, that small change in load rating won't make much (if any) difference to the squaring up, but the change to a different brand and construction might, so you're covered on both bases.

Don't go too high though (91 to 94 will be fine, but not 100), as you might end up with a more fidgety ride as the sidewalls may be stiffer and transmit more vibration.

[DickSkruttock]

mmm-five said:

Well, that small change in load rating won't make much (if any) difference to the squaring up, but the change to a different brand and construction might, so you're covered on both bases.

Don't go too high though (91 to 94 will be fine, but not 100), as you might end up with a more fidgety ride as the sidewalls may be stiffer and transmit more vibration.

Cheers mate