Mishimoto vs. Koyo

[S14DB]

Originally Posted by Silverbullet

If you want to speak in terms of power the engine makes, the more heat you take out with a radiator, the less power your engine is potentially making.

Wouldn't that be the job of the thermostat? Why you loose MPG with a colder thermostat.

[Silverbullet]

Originally Posted by S14DB

Wouldn't that be the job of the thermostat? Why you loose MPG with a colder thermostat.

Off topic,

I'm not sure what your asking me, but a thermostat just controls the temp of the engine by opening the thermostat valve when the water temp is at a certain temp. I couldn't tell you specifically why MPG is reduced with a colder thermostat, but it could be because more heat is taken out of the engine, or because the computer changes the AFR, or a combination of both.

Neglecting a thermostat, the more heat an engine produces, the more power it is making. About 1/3 of the total energy of the mass of the fuel in the combustion chamber becomes usable work (power to the flywheel). The other 2/3 of the energy is either taken out from the cooling system, or loss through the exhaust and other misc losses.