Originally Posted By: Wilhelm_D
Originally Posted By: AlpineM52
Would having the regular green stuff in there do any harm?
The issues would be silicate levels, G 05 and G 48 being pretty darned low, and life of service, G 05 and G 48 being long-lived.
I would assume the "green stuff" to be good for no more than two years and do a thorough flush at the end of that period and return to G 05 or G 48.
Caveat: be darned sure the mechanic flushed it thoroughly before filling it. If the contents of the cooling system are a mix of coolants, all bets are off.
This. I don't think G-05 is any better of a suitable replacement for G-48 than conventional Green. G-05 has a longer service life than Green though and Green is phosphated but that is not an issue even the water isn't hard. The real issue is mixing G48 with Green or G-05. From what I know of G48 is it's 2EHA with siicates and no nitrites but may have borates. Any coolant besides G48 is not going to be that similar of a forumula. I personally think the BMW would be OK with Green, G-05, Peak Global or even Dexcool. The key thing is get a full fill of one formula or the other and not a mix of coolant types.