I have another practical question for you peeps:
So, for last few days I drove the car like I stole it at times - not sure why just for fun I guess, shifting close to red line in several occasions.... In the process, I found out that you can almost hit 100 km/h in the 2nd gear, before red line.
However, not sure if this had anything to do with it, but I also noticed today that the oil level dropped a bit from where it was for few months since I had the car (middle of min-max interval). I know because I've been constantly checking the oil to get a sense of an eventual oil consumption - no dipstick as you know and this engine is known of burning some oil aside from leaking (which it does not).
Anyway, not sure if the oil level dropped for good or not - need to monitor it in the next few days since I've seen it before where the level went up from one check to another (didn't think it makes oil but rather a reading flaw), but the bottom line is that I'm about 3,500 km away from the next oil change so I may need to top it up if indeed the oil level drops consistently over the next period.
Now the wrinkle is I don't know with certainty what brand/grade of oil I have in the car. Don't ask me why provided I did an oil change at our common friend's shop after I got the car, so I should know for sure, but the reality is I don't. It should be BMW OEM (this is what I asked for and told it was done), but by other accounts, could very well be Motul as I was told in another occasion.
However, the grade is totally unknown and unverifiable at this point after few months from the oil change.
So, this car could take 0W-30 (I learned from my local dealer that this is what they put in if you go for an oil change at the dealership), 5w-30 (original BMW spec), 5w-40 (commonly used by shops for German cars and this one in particular). Even if the oil is BMW OEM and not Motul - the grade could be any as BMW sells them all and I don't know for sure which one they might've put in.
Now, IF I find myself in the position where I have to top it up until the next oil change, what oil should I use? I'm pretty sure none will do no harm to the engine, but still... need to pick one out of three possible grades. What should I pick?