I have been running synthetic 5w30 ever since I purchaced the bike with only 400km.. Do you think I should switch to 0w-40? I am due for an oil change in the next couple of weeks.
I think it would be good to stick with the 5W-30 full synthetic if that is what you have been using. I use Rotella T6 5W-40 in all my bikes since around 2004.
Keep in mind that once the motor warms up then effectively only the bigger number really matters. The 5W or 0W only really have to do with oil being thinner when it is coldest. Generally that number in front of the "W" is the viscosity of the oil at ZeroF (-17.8C). As the oil temp warms up the viscosity increases to the bigger number after the "W" until it is at normal operating temp where the oil is at that high number viscosity. The "W" stands for "Winter" temps. That is an extremely simplified explanation.
Do you change your oil for winter riding and then again for summer riding? I don't and I look in my manuals to see what the oil viscosity chart says to use. There is usually a range given that shows what viscosity is recommended for a given temp range from low temp to high temp. If you are riding when the outdoor temp is at or below zeroF (-17.8C) then you will likely be fine with the 0W-40 or 0W-30. But when the temps warm up to well over 32F (0C) then you really should replace that with the 5W-30, 5W-40 or what ever your manual says to use. Has to do with how well the oil viscosity goes up with temp and if the oil is too thin to keep a layer of lube on the engine parts when at rest or if it is thick enough to keep parts lubed when at rest and cooled.
I do ride at the zeroF and below temps and I find the 5W-40 works great on all my bikes at that temp to get them started. After warm up all that really matters is that bigger number as I mentioned.
