Originally Posted By: HangFire
0w-30 will help you get about 1-2% better MPG in Winter until your engine warms up, which means you'll never see the difference in a measurable way.
Of course it won't hurt your engine at all. The way I see it, if a quality synthetic 0w-30 happened to be on sale for less than your usual 5w-30, there's no reason not to try it.
yep, that's it.