Quote Originally Posted by D_A View Post
That's something I've considered trying in a car for ages, except that oil transfers heat far slower than water (but still better than air). I still like the idea, I'm just not sure how to make it perform well enough. Yet.
You are right, but the heat absorption capacity of oil is much higher than water, in that oil can withstand very high temps which would not be acceptable to water. This could be a good solution if you plan to run your system hot.
This also means that you do not need a high flow of oil. Pumps can run a lower rpm, less coolant volume, smaller diameter tubing, etc. Nevertheless it may mean larger radiator to dissipate heat. An interesting subject for a study anyhow.