"BMW - Oil Change Frequency"
23 April 2016
Summary: at least once per year and on high mileage, every 7,500 miles.
Own and maintain BMW's: 1997 Z3, 60,000 miles; 2000 X5, 201,000 miles.
Both cars bought new.
Use BMW 5-30 synthetic or Mobile 1 when on sale.
Always change oil filter with oil and only use BMW filters (Had problem of filter disintegration using non-OEM).
Neither car uses oil. X5 leaks around oil pan gaskets and Z3 leaked around valve cover gasket. In neither case did every have to add oil between oil changes.
Oil Change Frequency:
Recommendation from BMW is oil change when dash display calls for it.
Dash will indicate oil change every 15,000 miles which is great except....
Dash display on oil is simply mileage and not indicator of actual oil condition.
Z3 at 60,000 miles gets very little use per year and thus reason changed once per year. If car does not get hot like occurs on short trip, condensation in oil does not have time to evaporate out.
X5: have had 2 oil separators go bad and had to replaced. First time, would blow cloud of white smoke on startup after sitting for day or 2. Second time, more dangerous as was getting "Engine Oil Low" warning.
To keep dreaded oil mayonnaise from forming (reason for "Engine Oil Low" warning), change oil every 7500 miles or at least once per year.
Nothing is more important than have correct, fresh, oil and to the exact amount.