If you are running 19" wheels the normal RRS tyre size is 255/50R19. However, specifically for winter tyres LR handbooks call for 255/55R19. ie a taller tyre.

Maybe this is a typo (if so it's in every handbook since 2007) - or is there some logic to it that I am missing.

Bob, I am running 255/50/19's on my RRS and they are perfect. We are deep in the white stuff at the moment and down to well below minus 20 most days over the last month. (Sweden if I didn't say!)

As long as the tyre side wall is reinforced so as to keep a good road contact surface, then just make sure you buy specific winter tyres rather than M&S or all-year rounds. I have learnt so much about winter tyres since being here, cold temp compounds are also important here too (mainly Nordic climates though).

It's worth investing in some dedicated good winter tyres (the best by a million miles in EVERY test, EVERY year in the Nordic countries are Nokian), and keep you won't regret it I promise you. Even if you have to buy from EU and ship, it's much better. I could help with some places to buy online and translation if req'd

Finally, I bought some 'winter tyres' as a special order when I was in the UK a couple of years ago - I think they were Mitchelin, but can't remember. They were terrible, just like driving on Lego bricks, so hard and scary.

Here they don't plough the roads so often and salt is useless below minus 6, so they had to find a solution - Nokian did.

ps - we also alll drive studded tyres which is sooooo much fun in an RRS or Quattro

Thanks Tornado, I had heard that Nokian are the best and they are available from one source in the UK. Good reviews from N America too I recall.

But I'm still wondering why LR specify a different size (wall height) for winter tyres on RRS.

I cannot understand the 55 sidewall issue either - all I can possibly think (guess) is that it keeps the wheel further from deep snow? By what, 25mm? (difference between 55 and 50).

I could understand if it called for narrower width, these perform much better than wide tyres (see how 2CV's cut through) - but sidewall, the mystery continues.

Also, 50 and 55 profiles in winter tyres are stock sizes, so not that either....