Best Tires for the Mercedes Benz Mercedes GLS500 (X166)

Disclaimer1. I differentiate strongly between “winter” tires and “snow” tires with all snow tires being winter tires but not all winter tires being snow tires. By winter tires I mean tires driven under varied winter conditions including dry, wet, slushy and snow roads under 7C and by snow tires, tires that are particularly good in purely snowy conditions. For this reason living in a city I predominantly use winter tires but when I go skiing or to places with more snow I switch to snow tires.
Disclaimer2. While my preferred summer tire is a Michelin I never chose Michelin winter tires (Pilot Alpin) as I find them exceptional in snow but not necessarily in overall winter conditions. This time I was forced to buy them as two full sets of my preferred Conti’s were warranty claimed with Continental (and claim accepted) and there was no other tire in my dimensions and in XL available.

Plus
Ultra quiet tire. While this is last on my list of requirements and one I don’t care about I have never driven on a tire that quiet – almost unnoticeable and this being said for a winter/snow tire.
Best snow grip and traction. Very good breaking in the snow. Highly predictable driving. Probably best snow tires I have experienced across my winter tires to-date although Bridgestone Blizzak LM22 and Dunlop Wintersport M2/M3 I used as purely snow tires were also outstanding.
Comfortable under low speeds up to 80kph. Especially predestined for cities and regular roads with lower than highway or expressway speed limits.

Reservations
Noticeable higher fuel consumption – on average almost 0.8-1.0 liter/100 km more.
Very soft and overly too progressive. While this is expected from a snow tire with a snow compound they are too soft for my liking even though in Extra Load version and even though I had to add 0.3 bar pressure per tire. Still not what I would like them to be. The relative softness makes highway dynamic lane changing a poor experience and one that I am never sure how the tire is reacting. Similar when taking curves at higher speeds the lateral holding and stability are questionable or at least causing doubts/concerns. Nothing compared to proper UHP winter tires I have used to-date
Lot’s of road feedback but in my opinion much too much especially above 80-100 kph. Perfect road/traction feedback up to 80kph
Never sure how they are going to react under specific loads and driving conditions which probably is the worst thing to say about a tire.
Limited FR protection.
Highest speed index available for my tires was H (210kph) which is understood if these tires are snow tires.
Also all four tires were so different that there was a problem with wheel balancing. Two were perfect, one ok and the fourth required extended road testing to get it within manufacturers norms.

Conclusion
Great for snow covered ski resorts and driving up to 80 km/h. I would definitely use them as a second set of tires dedicated to pure snowy conditions. Otherwise for winter slush and varied road conditions in city and on highway I would opt for other tires.

The WT M3 used to be 10-12 years ago one of the best winter tires I used (the WT M2 was better for pure snow and the WT M3 for winter slush typically found in towns and on intercity roads). Then came the 3Ds 4Ds etc and I moved to other producers and tire makes so I was happy to find the tire available for my Mercedes with a M0 homologation (this also speaks about the tire after so many years in production). The only alternative (given 109 index and 265/55/19 size requirement) I had for the Dunlops were two Pirelli's (Ice & Snow and Scorpion Winter). First I find the Pirelli's overrated and two after my experiences with other premium producers with tires made in Russia I would not buy a tire made in Romania - whatever Pirelli says. The WT M3 is generally an excellent tire for all round winter conditions. If you live in mountain areas where you get snow all time I probably would go for another tire (if available size wise). However I do go skiing several times a year and the tire never gave me any problems. I would wish that lateral holding on snow would be better but this is an issue with most of the tires I have tested privately over the last 3-5 years. As noted aquaplaning resistance, steering precision on dry and wet with speeds up to 210 km/h (index H) and I have driven them around 180-190 are excellent. Noise I don't care about overall and especially the car is well noise insulated. Even if loud I would have bought them for the other parameters mentioned. 12'000 miles and still 6-6.5mm of tread left so very decent. Breaking is reassuring on dry and wet (in my opinion being better in wet than in the dry). Curve holding excellent (except in snow when the car tends to oversteer). Fuel economy is weak but this is the price you pay for grip - also with a car with a V8 biturbo and after tuning over 500KM of output this is of least importance. Overall highly recommendable especially if you don't have too much of a choice.

Mounted on a 2.5 tonne SUV with 500+ bhp although not used for aggressive driving - more offensive. I took off the Michelin Latitudes that came originally with the car after 1000 km as they were disastrous (or at least not meeting my expectations from a UHP SUV tire). The tires I typically use on my SUV were not available in 275/50/20 nor 265/55/19 (I typically don't go for 295/45/21 etc especially on SUVs and heavy vehicles). Overall extremely pleased with it to the extend that after 1 season (ca 20'000 km I had 5mm of tread left) I bought a new set. The wear is not a surprise given the grip the car has through the tires nor the fact it is a powerful and heavy SUV. Expecting much more would be a sacrifice for other parameters or difficult to achieve. I don't agree with the user mentioning their noiseniness. On contrary I find them very quiet although this is not an issue for me. The key parameter is Aquaplanning and breaking in wet and dry and in this respect the tires scores high. The only reservation I would have is lateral aquaplaning and lateral acceleration on the wet (I tended to get occasional oversteer however when driving at the limit and with a powerful engine). Altogether I prefer oversteer to understeer. Recommendable although I would prefer the QuattroMaxx is available in this size. A pity with the quasi cartel collusion of tire producers with OEMs is that nowadays you tend to get 1 maybe 2 tires that fit your car making the choice rather of lesser evil than a studied decision - not to mention additional pain adding brand homologations.