Originally Posted By: SteveSRT8
Once again everybody is generalizing. This info is not absolute, it is extremely platform dependent.
If you have a conservatively tuned econocar the oil is not heated as quick as if you have a fire breathing large V8. Then factor in some engines design: oil squirters aimed directly at the underside of the piston crowns, for example. These engines will heat the oil very quickly.
In our fleet vans the oil is run through the coolant, so temps tend to advance almost in lock step. In the SRT8 oil temps will out pace the water temp in all but the coldest weather.
Great points and all true. But, in MOST cars, the water will heat up faster due to shut thermostat and engine design where water is for cooling and oil is for lubrication (oil squiters at piston bottoms and turbo chargers are not common). This (water heating faster than oil) is the case with my high performance Corvette's V8. But, eventually the oil temperature is higher (10 to 15 degrees) than the water.