ok so i do intend on riding y bike in winter but wondering should i use 10 40 or stick with 20 50.......and can the 10 40 be regular car oil??? or doe it have to be bike oil??,.,,,

I used Rotella 15-40 diesel oil, for this winter. I dont think its a major sin, since I keep the oil change interval between 2300-2600 miles. Lots cheaper, 7.50 Gallon at wally-world.

I used to ride in Wyoming year round in freezing temps--Just use your regular oil and change as normal (I do mine 2500-3000 miles). Make sure you let it warm up thoughly.

Really, when you think about it, do you put different oil in your car? Unless you are in some serious sub zero all the time weather your regular 20-50 which is in the bike will be fine. Do you keep it garaged? If you do, don't worry. If you don't just let it warm up really good.

20-50 synthetic might be easier on your starter and battery if you don't have a heated garage.

I'm using Rotella 15-40 in my Yamaha for several years now. No problems.