Originally Posted by
langer
I use 10/60 every time. 5 is way to thin for a cossy. Every time this question pops up it opens a whole can of worms so to speak.
Not all 10W-60 are good. For cold days it's way too thick, even if its 10W.... to much torture for the bearings etc. and you need a longer warm-up time.
So many urban legends about the oil. 5W isn't too thin, it is only the cold visco. A 15W-50 is too thick for cold days and bit thinner at temperature. A 5W-50 is very well and strong for cold and hot driving.
Even a Mobil 1 0W-40 is stronger than most people think (forget the myth about the engine is too old, way older engines tolerate 0W-40). First filling by Porsche, BMW and so on. Only the hot visco after the W can be too thin (for example a 0W-20 or 30 were too thin) but never a cold visco. People have to mind this fact.
the biggest difference about the cold and hot visco is the best (exceptions some ester oils):
0W-40 (not 5W- 10W- 15W-40)
5W-50 (not 10W- 20W-50)
10W-60 (not 20W-60)
Sometimes less is more.
Had never much oil consumption in the cossie with 0W-40. But now I've 5W-50 for the daily driver.