I agree with everything Sport Billy said.
I tend to use the time spent in the res analogy because peaople tend to think of the res as a great wealth of cool fluid. In reality, the total res volume turns over on a second to second basis. Even if the 3 cup res were copper, very little cooling would occur. Couple that with the fact that reservoirs are usually plastic, very little (if any) cooling occurs there.
For the reasons that Sport Billy already stated ..... the rad does the cooling. The res is simply along for the ride. |