Just to muddy the waters, and not sure if it applies to vancars.
michelin.co.uk:
”
Can I choose a winter tyre with a tyre speed index lower than the one recommended by the manufacturer?
Yes, if the vehicle is equipped with winter tyres (marked M+S and 3PMSF), which have a speed rating lower than the maximum speed of the car, their fitting will be legally accepted, provided that a clearly visible sticker indicating the maximum speed of the tyres concerned is affixed in the driver’s field of vision.
For example: on a car with a maximum speed of 205 km/h, tyres with a speed rating of H should normally be fitted. If winter tyres (marked M+S and 3PMSF) with a speed rating of T are fitted, a sticker indicating that the maximum speed is 190 km/h should be affixed.
“
Link
I cant find the “rules” or “legislation” that backs the above up.
We have a MK IV Golf which requires H rated tyres but getting H rated tyres with 3PMSF is not easy (or cheap) due to the weird tyre size. T rated versions seem to grow on trees, though.