I don't think synthetic oil is worth the expense so I don't use it in my (non-turbo) Outback or Quest. The Quest lived in Anchorage briefly, and my other cars lived outside there for 20 winters and they always cranked ok, even if I was away from any block heaters skiing into a cabin or something.
Now the Quest is in Boise, where we have hot summers (105 isn't all that unusual), and it's puttering along ok at 125,000 miles on plain oil changed on a 7,500 mile interval.
I drive them forever too - the Outback is a '97, the Quest is a '99 and up north I ran a Toyota on dead dino for 17 years.
Now, if you really were asking, of those of you who use synthetic, what brand... then nevermind. -)