How did you come to this rate? It is dependent on the restrictions in the head/block vs. radiator. You are saying they are perfectly equal.

Not only that...Heat expansion of the coolant (thereby affecting density) would probably play a role in what portion would flow thru the rad at different stages... But...why would you want to run your Benz without the Tstat? The extra cost in fuel (while reaching operating temp) ought to be prohibitive... no?

good point.

I do not wish to run w/o t-stat. I am simply supporting my claim that the engine will OVER-cool until a critical point is reached.

Others have said that it will UNDER-cool.

All b/c a member mentioned that he modified his t-stat to flow more.

All I can add to this depbate is that if your t-stat won't close completely you will run too cool. I just swapped mine out today. Before the swap, with half the radiator blocked with cardboard (a temporary measure to try to raise the temp) it never got above 70*C (160*F) in city traffic, and spent a lot of the time down closer to 50*C (120*F) on city streets.

After putting in the new one it runs right about 85*C - 95*C (185*F - 205*F) on city streets. Haven't had it out on the highway yet. I was getting about 24 mpg around town before. I expect that will go up 1-2 mpg now that it is operating at the more efficient proper temperature.