You could cool the engine / coolant significantly, but that too much would not be good for 2 reasons: 1- For our good Canadien friends, if the coolant was too cool , you would not be able to heat the car in the winter
2- The engine has been tested to operate the most effienciently at its designed temperature. The explosion inside of the cylinder will take place when the heads / block are at its optimum temp, therefore, maximizing power / mileage.
So don't go removing your thermostats now!
'89 420 SEL
'90 300 SEL
'68 Olds 88 Convertible
'84 300 SD (sold it)