Two key criteria for a tyre are
1) A rubber mix defined for good grip in the expected temperature range - true "summer" and "winter" tyres operate best in their design ranges - summer tyres are too hard in the cold and lose grip - winter tyres are too soft when hot and may not grip ideally and can wear badly. Cross climate tyres use a compromise compound that works well in temperate climates and also appeal to SUV users
2) Tread design - lots of blocks and/or channels help water dispersion to prevent aquaplaning and help grip in snow/mud - so winter tyres have lots of blocks/cuts - these blocks move around and get hot when going fast so winter tyres are often speed limited. Cross climate tyres have tread designs closer to winter tyres so are often good for wet grip/aquaplaning.
Our M3W (like many others) has a cross climate on the rear for confidence on wet grip - on our Boxster we go all the way with 2 sets of wheels for summer/winter. Suspect in our climate neither get tested to the limit but on this kind of safety issue, caution is good.
However, biggest concern for me is usually the way people run their tyres all the way to (and beyond) the 1.6mm legal tread limit let alone to the typical 3mm wear indicators...this has biggest negative impact on wet grip/aquaplaning - we usually change well before the wear indicators and this also ensures the tyres are not too old (5-6 years seen as max recommended as rubber hardens over time)
Absolutely that - and nicely put. One of the biggest risks for our 3-Wheelers is rear wheel aquaplaning, as when that happens there is to all intents and purposes zero vehicle stability and accidents are extremely hard to avoid if the speed and momentum are there to hinder you. An All-Season tyre (Michelin Cross Climate, Vredestein Quatrac, Goodyear 4-Seasons Vector, Conti AllSeasonContact etc etc) are in my view the best for the M3W as they offer far better wet grip and aquaplaning resistence than a typical 'summer' tyre. The very worst rear tyre for our cars would be something like a Michelin Pilot Cup, Pirelli P-Zero Corsa or similar - but fortunately none of those come in 15" size. Toyo R888-style tyres do however, and I'd avoid those like the plague to be honest, as they offer very little water dispersal in order to get more rubber onto the road, for what is a very popular track-day or wet-weather (fine on 4-wheelers) clubmand race tyre. Our cars handle best with a balance of grip front-to-back, and with a pair of tiny crossply's on the front we hardly need a sticky slick on the back (for road use at least). Add into the mix that an All-Season will give better grip on grass or on mud (the inevitable British summer day out....), then it's the all-round best choice as far as I am concerned.
