Winter Tyres Setting on MFD

[MK6-Fan]

On my 2012 MK6 Golf 'Match' I was browsing the options in the MFD the other day & came across an option about Winter Tyres.  Does anyone know what this setting does? 

Thanks

[Jimble]

It warns you if you exceed a maximum set speed for when you have winter tyres fitted.

[Booth11]

If you have it enabled, I believe it gives out an audible warning alarm as you approach the max speed for your winter tyres (which will have a max speed rating). 

[RocketRossUK]

I thought it was for the reduction in speed when having thicker tyres on, for example changing to 225x50x18, it has a slower rolling resistance over 225x40x18 therefore you adjust your speedo to give correct reading

[Ess_Three]

I thought it was for the reduction in speed when having thicker tyres on, for example changing to 225x50x18, it has a slower rolling resistance over 225x40x18 therefore you adjust your speedo to give correct reading

The winter tyres you fit are supposed to be the same rolling circumference as the standard tyres.
VW fit 225/45/17s and 225/40/18s which are pretty close.
The suggested winter tyre size is 205/55/16 (I think) which is again, roughly the same rolling circumference.

As long as the rolling circumference is within a few % there is no need to re-calibrate the speedo - although you need to reset the Tyre Pressure Monitoring or it thinks you have a puncture!

I believe the warning is as stated, to warn you of the speed limit of your tyres, as winter tyres tend to be lower rated than summer tyres.

[RocketRossUK]

I thought it was for the reduction in speed when having thicker tyres on, for example changing to 225x50x18, it has a slower rolling resistance over 225x40x18 therefore you adjust your speedo to give correct reading

The winter tyres you fit are supposed to be the same rolling circumference as the standard tyres.
VW fit 225/45/17s and 225/40/18s which are pretty close.
The suggested winter tyre size is 205/55/16 (I think) which is again, roughly the same rolling circumference.

As long as the rolling circumference is within a few % there is no need to re-calibrate the speedo - although you need to reset the Tyre Pressure Monitoring or it thinks you have a puncture!

I believe the warning is as stated, to warn you of the speed limit of your tyres, as winter tyres tend to be lower rated than summer tyres.

Yeah i know you are "suppose to" adjust rim diameter with tyre, i know people who dont. If you are going from 40 to 45 or from 45 to 50 the rolling road speed changes.

I thought thats what it was for, but you could be right as i have never used that feature 

[Ess_Three]

Yeah i know you are "suppose to" adjust rim diameter with tyre, i know people who dont. If you are going from 40 to 45 or from 45 to 50 the rolling road speed changes.

I thought thats what it was for, but you could be right as i have never used that feature 

You only change the tyre aspect ratio by 5 if you change the diameter.
You won't get, for example, 225/50/18 tyres to fit on a Golf!

For every 1" diameter you go up, you drop 5 on the aspect ratio...assuming you keep the width the same.
So people don't bother because the new tyres are close to the old tyres in their rolling circumference.

[dubber36]

For every 1" diameter you go up, you drop 5 on the aspect ratio...assuming you keep the width the same.
So people don't bother because the new tyres are close to the old tyres in their rolling circumference.

That will be correct in some cases, but is a bit of a sweeping statement that could misinform some interneters. Changing up from 205-55-16's for example would require a 225-45-17 tyre to keep the rolling circumference somewhere near the same.

There are various tyre size calculators around to help people select the correct size tyre for their upgrade. Some even take into account wheel widths and offsets like this one. http://www.tire-size-calculator.info/

[Ess_Three]

That will be correct in some cases, but is a bit of a sweeping statement that could misinform some interneters. Changing up from 205-55-16's for example would require a 225-45-17 tyre to keep the rolling circumference somewhere near the same.

There are various tyre size calculators around to help people select the correct size tyre for their upgrade. Some even take into account wheel widths and offsets like this one. http://www.tire-size-calculator.info/

That's why I stated "assuming you keep the width the same".
Clearly going from a 205 to 225 wide tyre changes things.

[spiderman]

If you have it enabled, I believe it gives out an audible warning alarm as you approach the max speed for your winter tyres (which will have a max speed rating).

This is correct, i have 16" winter wheels and tyres for mine and when i changed them last winter, i set the max speed warning on the MFD just for a laugh to see what it does, it goes "bong" like it does when you get an ice warning, massive anti climax

The only thing you have to do, is reset the Tyre pressure warning once it goes off and then it re-calibrates to suit the new wheels, you have to do it again when you switch back in spring.

Sandy