I recently noticed that my overflow reservoir was completely empty, and after opening the radiator cap I couldn’t see any coolant. Obviously there could be a leak though I haven’t noticed anything and am thinking that I just need to top up both the radiator and overflow.
My only concern is with mixing coolants with whatever is currently in there. I’ll be getting a full drain and re-fill done when I can but am hoping to get me through until my next service.
Would it be fine just to fill up both the radiator and overflow with generic green Supercheap coolant? Or even distilled water? H6 engine, from what I remember, manual specifies 50/50 water and ethylene glycol.