Originally Posted by TuefelHunden
My point is if you are expecting something new in any oil thread, stand by for disappointment.
That, Sir, is all well.
The first post in this thread, however, tries to point out that I am not trying to collect what all the
fine gentlemen having a Gin Tonic here this afternoon happens to consider to be The Best Oil for
their own, or some other's engine.
In fact, I am trying to establish what you might very well consider the opposite: What BMW, the designer
and manufacturer of the engine, actually requires.
It is this assumption I would like to put in the GSpot FAQ.
Let us also, without delay, remove the producer from this. As of today, it seems as if Castrol won the
bidding and purchased the spot which BMW had left open in the manual. Next year that spot
will go to Statol, AGIP, Exxon or some other producer. We are not at all interested in
who was willing to fork out for that spot this year.
As far as I know the manual for the wethead (the 2013-model, water-cooled R-engine) has in it the
magical formula "5w-40" to indicate viscosity and "API SL JASO MA2" for the quality of the oil.
That is fine, and it has been copied into the GSpot FAQ In Verbatim and In Extensio.
Now, having covered all that which has been covered earlier in this thread, let us get right down to
the question at hand: Can I use 10w-40 in the wethead? And please do note that this has
been recommended more than one already.
There are two valid answers to this question: No (because BMW, the designer and manufacturer of the engine,
explicitly asks for something else), or Yes (becuase [...]).
The crux of this thread is this: What needs to replace those dots for Yes to become valid.
For example "The definition of viscosity means that above 0 C, an oil which meets 10w- will be
identical to 5W-......." with a reference where I, and other m3ere mortals, can enlighten ourselves,
that, Sir, is what I would very much like to have.
As a side-effect: If no-one can produce any substantial information on this, pointing to this thread will
enable us to shoot down he 10w-40-advice whenever it pops up in future oil-threads regarding the wethead.