Oh crap! I didn't use BMW OEM antifreeze!

[Jeg Norge]

i think the coolant capacity is about 12 Liters (3+ gal), so i dont think 8 oz of another coolant is actually going to do anything harmful.

[ard]

Originally Posted by Jeg Norge

i think the coolant capacity is about 12 Liters (3+ gal), so i dont think 8 oz of another coolant is actually going to do anything harmful.

I think you want to do some reading on coolant chemistry and what cause precipitates and corrosion... it is not a volumetric phenomena, but rather very small amounts of impurities (ie ~1%) can cause issues. An incompatible fluid MIGHT act as an impurity.

I'm not saying this mixing of an unknown coolant into the BMW fill is an issue, but I am saying that dismissing this by thinking "It wasn't very much" is wrong.