I have a 05 545i with about 82k on it. This morning I started the car and let it run for about 10 minutes because it was cold outside. When I drove off I got an "engine oil at minimum level" I do not have any drip marks in my drive way and the car is running fine. I just got an oil change about 3-4k miles ago. Also after I stopped at the store this morning and restarted the car the warning went away.

Is this normal for me to have to add oil, between changes even if I am not noticing it leaking?

What grade should I use? I a have left over bottle from the last time I had the car serviced at local shop the guy used AMS 5-w 40. I am not sure that that guy knew what he was doing. Is that good oil and the correct grade?

Please recommend the best/correct oil for me to use

 

Outside Europe you should use BMW LL-01 specification oil.(In Europe it is BMW LL-04).AMSOIL do a synthetic 5W-40 for European models so you need to check the bottle label .If you have ambient temperatures below -20C , 0W should be used rather than 5W.

 

If you live close by the dealership, just stop by at the parts department and grab a bottle of bmw oil. It only cost about $9.
Plus, may I ask why are you let your engine idle for 10 minutes? That would be actually bad for the car rather than help to warm up the car in cold environment.
Also, the reason you get the low oil warning disapear and appear again is because you are probably at the slightly above the trigger level.

Hope this helps.

 

When in doubt use the dipstick. if you're not sure what your mechanic used then just drain and fill. I use castrol 0w30 full synthetic, and it says it meets BMW LL01. I think Mobil 1 also have an approved oil. both about 7 per bottle, and you need 9 quarts.

 

Dipstick? I can't seem to find mine

 

only the V8 had dipsticks on pre LCI. I'm not sure about LCI models.