Engine Temperature

[Wisha Haddan H3]

Since switching to synthetic oil (mobil1), my engine temps are more stable. I was able to use the A/C crawling around hells revenge in moab last month and the needle stayed just above center.

And switch back to 50/50 coolant. At 70% water, you're not doing your engine any favors.

Coolant has 3 main jobs ... keep the liquid from freezing, keep it from boiling and help with heat transfer. Using the right ratio of coolant to water raises the boiling point and lowers the freezing point to the most extreme temps. And although water alone has a higher specific heat than coolant (it carries more heat per unit of volume), it transfers heat much slower. A 50/50 mixture creates the right balance between the amount of heat carried and the rate it can be carried away.

Some people swear by water-wetters to reduce engine temps. I have no experience with them, but maybe others will chime in.