BMW's coolant is affordable, safe for our cars, and discounted for members at local dealerships. You'll need a gallon or 2 to use along with your distilled water. BMW of Sterling has a special...

Yearly will work, changing it before you put the car away for the winter. Acids can build up over time in the oil/crankcase, as well as in the cooling system. Are you changing the coolant every 2-3...