Antifreeze Prestone or OEM Toyota

I run the prestone green coolant in my e36 since 2006 and my 540i/6 since 2008. They're both fine. The old engine still looked & ran great. The radiator in my 540i was still from 1998 until very recently when I did a cooling system refresh - entirely preventive.

Prestone teal colored euro coolant has never failed me.

I use the Prestone 50/50 Prediluted coolant which states “guaranteed for all vehicles American/Asian/European” on the label. It is yellow/green. Zero issues because it matches the specs in the manual.

I use Prestone teal European car formula. No problems yet

OE BMW coolant should be your first choice, and if it can’t be, second would be another reputable coolant maker that offers a European vehicle variant. For example, Prestone makes a blue in color variant formulated for use in euro cars. I’ve used both, never had an issue with either.

Replace the orange stuff with new Prestone orange stuff.

For coolant - cheap Prestone (concentrate) got my old Speed3 to 60 000km no problem. I used 25% glycol and 75% distilled water and a couple caps of redline water wetter. No more overheating, even idling in +35°C.

for choosing coolant, if just topping off, i use whatever's already inside. so if it's factory coolant, use Toyota OEM coolant.

Prestone does work, but Toyota uses RTV to seal the coolant passages between timing cover/thermostat housing and engine block. Prestone uses 2-EHA which has been shown to be aggressive on silicone, however it’s not uncommon to see leaks with the OE coolant that uses sebacic acid which is also a plasticizer. That said, I have a Sienna and LS430 that’s filled with Prestone, no coolant leaks… yet.

Prestone destroyed my passats Cooling system, everything just deteriorated, the hoses in my car started to break up. I don't recommend prestone