Water/oil cooler

[Stealer Of Souls]

Strange title... but anyway, I've noticed on TM that there are a few cars out there which come factory fit with an oil cooler that utilises water....

What I'm wondering is... where does this water come from (is it piped in with the normal coolant system, or more like a separate Water-to-air intercooler), and how effective are they?

[atmosports]

Generally they just use the same water/coolant as the engine, effectiveness varies from engine to engine but they are useful on engines where the water temperature is a lot less than the oil temperature helps to balance them out or vice versa. Generally allows quicker warmup than an oil-air heat exchanger although probably not as efficient once the water gets hot obviously.