Bmw wouldent agree with you Neilda but i do exactly the same as you every 5k.Even so i still have the famous vanos rattle on start up just for a second or two like most x5 and aero owners,I have also never topped up the oil between services and the oil comes out quite golden.
Em
I only have 2,500 on my engine so far, but everything I've read about this engine suggests that oil quality is paramount to a long engine life. An oil change is not that expensive and for a quality engine (which this is) it can only do good.
I have no rattles on mine, the engine is virtually silent.
Interesting thread here on a rattle which turned out be something else...
http://www.pistonheads.com/gassing//topic.asp?h=0&f=72&t=841163&mid=0&nmt=Vanos+beginning+to+rattle+-+what+are+my+options%3F
