During temperate months, 10W-30. If you live where it gets uber-cold, run 5W-30 during the winter. If you live in places like Buffalo NY, Alaska, Minnesota, where you can see near Arctic temperatures, run a 0W-30 during the coldest months.What oil do you guys use?
Modern synthetics have an additive that helps swell the seals so you don't get new leaks. I'm definitely not a synthetic engine oil fanatic but it would definitely help your engine crank faster in that -22 weather as well as flowing into the engine's nooks and crannies faster during cold starts. For non winter conditions, I'm all about using nothing but conventional engine oils.I'm from Michigan, use 10w-30 in Summer, 5w-30 in Winter...down to -22° once and still cranked fairly easy. Any colder, I would do what Jerry said on the 0w-30! I only use conventional, I have heard that switching to synthetic may aggravate existing leaks.