BMW Questions? Ask a BMW Repair Expert for Answers.
You will need to use the Blue coolant. This is something that you can purchase at a car parts store or at your dealer. If you are close to the dealer they will top this up for free for you with no expense to you. The type of coolant is called Etheline glycol. To add coolant you fill the reservoir. The reservoir tank is a large tank with a black cap. If you are just doing a top off you can add a small amount of water but it is better to use the 50 / 50 mix of coolant and water to maintain freeze levels.
I hope this is helpful. Please accept and best wishes to you.