How does oil temp correlate with water temp?

[dsmith41]

When you start your car in colder temps, does the water heat up quicker or slower than the oil? Is it safe to say that when your water temp gauge gets up to operating temp, that your oil is at operating temp as well?

 

[expat]

NO! To reach optimal oil temp can take about 20 mins at Highway speed. Water temp rises much more quickly.

 

[webfors]

Water/coolant temp reaches temperature very quickly. Oil temp can take 15-20 minutes.

 

[hannaco]

It also depends on the design of the car. Audi/VW uses an oil cooler/heater that has a water jacket supplied off the water pump. The oil is either heated or cooled by the engine coolant.

 

[Vilan]

Water transfers heat much faster than oil, which is why radiators are filled with water-based coolants in the first place, rather than oil-based ones.

 

[Bruce T]

When starting a cold engine, the thermostat remains closed so that the coolant flow bypasses the radiator. This makes the coolant warm up faster than the engine oil. When the thermostat reaches a preset temperature (180-195°F), it begins to open so that the coolant can flow through the radiator.

On top of that, modern coolant gauges are typically "idiot gauges," so that the needle quickly jumps to the center and stays there -- before the coolant is fully warm. Why? So the dealer can avoid complaints from customers about high temps.

 

[lipadj46]

Originally Posted By: Bruce T
On top of that, modern coolant gauges are typically "idiot gauges," so that the needle quickly jumps to the center and stays there -- before the coolant is fully warm.


Ain't that the truth. Anyone driving around with a scanner hooked up knows that the temp "gauge" in their car might as well be a warning lamp (on or off). If your needle moves it is usually too late and your car is already severely overheated.