[Zyzzyx]

Had some work done on the car this week (t-belt, water pump, t-stat, and other stuff). With the change of the thermostat came a change in the operating temperature of the car.

Looking back I should have realized that the car was running cool, especially the last couple weeks since I got the ScanGauge and had a digital temp reading. Most likely the t-stat was opening way too early, or even staying open slightly. The cars 'normal' operating temp was ~165F, and would cool down when in DFCO, sometimes quite noticeably (down to 120F on one long downhill in 5th gear). Thus it was still flowing coolant through the radiator and cooling it even when then there was no extra heat load.


With the new thermostat I'm now seeing the factory gauge "where it should be", and the digital gauge is telling me ~195F (its a 188F t-stat, tested and it does open right at that). Also the engine temp is steady now on a long deceleration with fuel cutoff.



So what I'm wondering, is there some efficiency gained now that the engine is running 30F warmer than it used to? I'd say the oil is slightly thinner at the higher temps, but that's questionable with the viscosity modifiers. What about the cylinders, any chance of better combustion with the warmer engine block?