Instead: Hydrate with H2O. One of the best measures you can take to avoid kidney stones is to drink plenty of water, leading you to urinate a lot. So, be sure to keep well hydrated, especially when engaging in exercise or activities that cause a lot of sweating. It's Not Just the Oxalate.
You didn't say what year or model BMW. The service intervals vary a huge amount between models a years. BMW built since the mid-1980s have a service indicator. You should change the oil when the service indicator tells you to. On BMWs that specify synthetic oil, you should change the oil when the indicator counts down to zero or once a year whichever comes first.
How often should a car's synthetic oil be changed? A: Synthetic car oil needs to be changed after 10,000 to 20,000 miles, depending on the climate and driving distances. The recommended non-synthetic oil change is every 3 months or 3,000 miles, whichever comes first. However, synthetic oils, which cost nearly twice as much as conventional oils, require less time between changes because of their ability to withstand high temperature levels.