10-02-12, 10:50 PM
I'm not the oil expert on this forum (or any other forum!) but for what it's worth here is my basic opinion.
Any oil gets thinner (i.e. viscosity reduces) as it get hot, even a multigrade. It also gets thinner with use. So when the oil is cold the gearbox may well feel smoother. However a thicker oil will not be good for the engine with the small oilways and small clearances on plain bearings. Hence why it is bad for the engine to be rev-ed too much before it gets warmed up.
I would stick with the recommended grade.
Any oil gets thinner (i.e. viscosity reduces) as it get hot, even a multigrade. It also gets thinner with use. So when the oil is cold the gearbox may well feel smoother. However a thicker oil will not be good for the engine with the small oilways and small clearances on plain bearings. Hence why it is bad for the engine to be rev-ed too much before it gets warmed up.
I would stick with the recommended grade.