Winter Tyres

[dzell]

Hi, I have a MK6.5 Fiesta on 16" alloys. I am curious whether it would be possible to run 195/55/R16 winter tyres as oposed to the 195/45/R16 that are fited as standard? Would the higher profile increase risk of rubbing in the arches?

The main reason for this question is the increased choice of winter tyres available with the larger sidewall.

Any advice would be greatly appreciated. Thanks

[Captain Haddock]

That would result in a +6.7% difference in rolling diameter; the recommended maximum is +/- 2.5%.

So it's not really a good idea as your speedo would UNDER-read; that is your road speed would greater than the speedo reading which would make judging your speed versus any speed limits very difficult and an easy way to get caught speeding.

I don't how easily available they are but 175/50R16 would be a -0.17% difference in rolling diameter and would would be better (speedo reads greater than road speed), plus the narrower profile would be better at cutting though any snow or standing water.

You should not use a larger profile during winter; slightly smaller is actually better as you increase the ground pressure (same mass on a smaller contact area). One thing you definately don't want is the "snow shoe" effect (i.e. sitting on top/aqua-planing) as snow or standing water gives you zero grip; you need the tyre to get through to be in contact with the road surface as that's where any grip comes from.

You can check the effects of changing tyre sizes here :-

Visual tyre size calculator

[kevzs960]

If your at standard ride height then they wont rub the arches. Person above is correct that your speedo will be diffrent due to a larger rolling circumfrence.

Ive got uni royal rainsport 2 (now rainsport 3 as there not availble anymore) and ive had no problems when weve had thick snow. I wouldnt run thinner tyres as your taking 20mm off the width of the tyre an you could be more prone to the tyre popping off if you curb it (hope you dont)