Antifreeze PEAK or OEM BMW

My car is currently filled with the Peak Euro Blue stuff, works fine, identical to the OE BMW formula anyway

I always use the OEM coolant that I pay an arm and a leg for from the dealership. For a few dollars it’s not something I want to chance in vehicles (especially my E46) with such sensitive cooling systems.

I personally use Peak brand coolant, and I've never had an issue for 100K+ miles.

Even though most will say to stick with G12/G13, I think that is where that "sand" comes from. I decided last year to completely drain the system - including engine block - and converted to Peak antifreeze. I have not had any problems since.