With my 82 733i and 85 528e the oil level light was tested from time to time because they were (are) "wet" engines. My 88 735i that I have had for over two years now has a dry engine and I had always wondered if the oil level feature worked. Well the first of the last week I noticed I had 8K on this oil change and on Thursday the message displayed and very strong chimes went off. I checked the oil and it was dead on the bottom dot so I now know it works and that at 170K miles the oil usage is very low. Yesterday I got it changed.