Do what your owners manuel suggests and you can't go wrong. It lists either 5w-30 or 10w-30, of which, 5w is used for winter and 10w is for summer. 5w-30 is fine for all around use. Do not use 15w-50 anything, because your car is not designed to use that heavy of an oil. What that will do is make your engine very hard to start in winter and cause more wear on the engine than necessary. It is designed for very heavy mountain or pulling a heavy travel all day type of use. Synthetic oil is a good way to go because the oil is more durable than regular motor oil. The extra cost is worth the price, but make sure that you stay at the same oil change interval.

Read your owners manuel too. It will help you a lot.:-)

Hope this helps! jm .02

Rick 97 850R, in Denver