I think it the thermostat is important. Running the engine too cold destroys the engine.

Like most expensive euro cars with Catalytic Converters, Mercedes for example, runs better with a hotter engine. these cars run at almost 95 to 98 degrees on the average.

On Opels too, if you run it too cool, palyado ang takbo and malakas sa Gas.

Nakakatakot lang talaga since it runs too near the 100 degrees mark which is an overheat!!