0w100 Synthetic Engine Oil

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I think I use 20w40 in my bike.

Concerning motorcycle oils the problem we have is that even with synthetic oil technology, motorcycle oils are usually marketed as 10w40 for Japanese bikes and 20w50 for American V-Twin Harley Davidson's.

A 5w70 would be an ideal universal motor oil for motorcycles. A 5w70 would have better cold weather performance than a 10w40 and it would have the same 300 degree high temperature high shear viscosity of a 20w50. How can an oil be too thick if it is the same viscosity at higher temperatures?

10w60 would also be a better choice than 10w40 or 20w50.

Funny you say that, my car is a bmw. Here is what the owners manual says for my specific engine
[img][800:608]http://www.bimmerboard.com/members/q/original/E34%20Oil%20Spec%20Chart%20M50TU.jpg[/img]

The modern high revving M cars are the only ones asking for 10w60. Which is done more because of the smaller tolerance of these engines yet high demands. They get away with this by having varying redlines depending on multiple factors.

Most old school mechanics would vehemently object to the use of a 10w60 synthetic oil. Instead they would tell you to use a 10w40 oil in the winter time and a 20w50 oil in the summer time. What mechanics do not understand is that a BMW oil change light will not come on until 15,000 miles which amounts to a whole year of driving.

Uh... I can read my odometer. Sorry if other people cannot. 15K oil change with any oil is ridiculous. I don't care if it's some fancy synthetic or whatever, it's ridiculous. I'd rather change more often and use conventional, personally.

I used to change ever 3000 miles, but I have been convinced that every 7500 miles is o.k.

So you would rather use a dirty conventional oil and change it with another dirty conventional oil every 3000 miles?

A dirty oil is still a dirty oil no matter how often it is changed. Distilling an oil once cannot remove all the impurities.