Antifreeze Concentration vs. Coolant Temperature

[jgl1]

Looking for information regarding engine coolant temperature as related to coolant antifreeze concentration. Given a properly functioning engine at operating temperature and static ambient conditions, in which direction would the coolant temperature shift(if at all) if the antifreeze to water ratio is changed from say 50:50 to 40:60; in other words, would the engine run slightly warmer or cooler? Would the reverse apply if the antifreeze concentration was increased?

Anyone have any charts on this information?
Thanks in advance.

[Mike Murrell]

JGL1

While antifreeze raises the boiling point of coolant, it does not dissipate heat as well as water. 40/60 coolant/water in theory is COOLER than 50/50. 60/40 coolant/water is HOTTER than 50/50. Some say that the ultimate "cool" trick is 15% antifreeze, water & 2 bottles of WATER WETTER(made by Redline). I've never experimented with this because coolant lubricates the water pump.

For what it's worth, I live in a fairly humid area of south Texas and I've experimented with 30/70 - 40/60 and 50/50. My MBs temp gauge reads the same with each of these concentrations. In the end, I suspect the best deal for your car is 50/50. Regards.

Mike Murrell
Boerne Texas
'91 300-SEL