Originally Posted by lightning20
Just had my light come on saying the coolant was low i don't live near a bmw dealership i think the nearest one is about 100 miles away so i need to know which type of coolant to buy. I searched and most just said to add water in but i think it would be better for a 50/50 mix but i don't know what kind to get i have a auto zone and a schucks near me also a wal mart so anything that can be found in those stores.
Depending on how much you need to add, distilled water is fine and you won't go that far off the 50/50 ratio. By the way, I wouldn't assume it's a 50/50 ratio for this car as BMW coolant can be different.
As for coolant, don't use anything but original. If the E90 is anything like my E34 (and I'll bet it is), it it vital to use the original stuff only. The additives are carefully blended to protect the metal alloys in the engine.
Let me put it this way - you're better off being off-ratio by adding distilled water than by using some other brand to top off. You can mail-order the OEM coolant for future use.
Hope that helps,