2003 BMW 530i Q&A
2003 BMW 530i Question: Is it harmful to mix synthetic and natural motor oil?
NO, BUT If it was that low, you've likely exceeded the time factor or miles for the oil and it needs changed anyway. Unless you have a significant leak, I can't imagine being 2 qts low. If it were mine, I'd change it ASAP. I used syn-oil in my 1999 323i and it never leaked, but would use < 1 qt. by the time I changed at 10k miles intervals. KIA at 235k miles and still running great. My now newer 530xi does not loose a drop up to 8k miles between changes on BMW approved Syn-Oil with 68K miles on the odometer. - Spudking