What is best for 2010 GL350 winter tires? Dealer recommends Pirelli scorpions, 265 (or was it 255) 19in. I know it was slightly narrower than the all seasons that come with the vehicle to cut through snow a bit better.....

Any other options, or better prices than dealers in Toronto?

Owners manual specifies which size winter tires to fit.

No "tire dealer" in the world knows more, but they are always anxious to move existing stock.

In this case, Kent, I would suggest that the OP be open to other options. In Canada there has been a shortage of tires, due to them being manditory in Quebec. It is true that a narrower tire will have slightly more bite, but 255 from 265 is likely not much different, and also within the range that tires would actually be between manufacturers. I can't say enough good things about the Nokian wr2g, you should see if they come in size you want. If you are buying rims, they do come in 265 60 18, it would be better than the wrong size, and a worse tire on 19s. 18s will clear your brakes, and the taller sidewall will also halp reduce float. Check Kal Tire.

just put on a set of 18" wheels and tires touren wheels and toyo snows. great grip but cant seem to balance so i think i must have got a bent wheel. taking it back to ok tire in van tomorrow. local benz dealer wanted 5200 plus tax for the 19" wheel and tire package. it would be approx 1600 for the wheels and tires from the tire rack but i didnt have the the time luxury. good luck also try discount tire on the net very competitive.