hello sages- have a gallon of go5 coolant and expect to flush and refill my 92 240 wagon. currently coolant is clean and green(surmise thats the standard green ethylene glycol). prior owner who took very good care of the car; replaced the head and gasket due to corrosion which necessitated a flush and new coolant a year ago just before i bought it. no problems with heat, temp control ,leaking etc. only issue telling me i ought to change and flush is the coolant is weak i think because my 5 ball tester tells me its only good to 5 degrees (two balls floating). while not an issue here in south fla it still seems weak. brickers here seem to be divided on coolant.some say green antifreeze is fine in this old 240. others say use the go5 which is better for the bimetals in the engine and b/c it is anti acidic . dont think i need to flush this unless it is necessary since it is clean and only a year old. is it ok to mix the two antifreezes (green and go5)? that would be easier since all i have to do is drain out a gallon and put in the go5 gallon. other question is some have told me the g05 will provoke leaking at the seams of the system? never heard that about any antifreeze, but have never used g05. uncle moe said just drain out a gallon and put in a gallon of regular green to concentrate the mix. hate to be a pain in the keester but really think i should rely on your advice. appreciate always your help. thanks tons oldduke