Can someone explain the diffs between an oil cooled turbo and a water cooled one? Pro's Con's price diff? thanks

I've heard oil cooled turbo's are not as reliable

 

All turbos technically are "oil cooled" in that some of the heat is carried away by the oil. Non water cooled turbos just rely *entirely* on the oil.

Here's a graphic from an SAE paper that Dodge did on the engineering process of the 2.2 Turbo, back in the 80's. They were trying to determine if the benefits of a watercooled housing outweighed the cost. The cars had watercooled housings, as well as practically all turbo cars made OEM since about that timeframe.



I see absolutely no reason why anyone would want to run a non-watercooled turbo. Unless maybe it was a rally car running huge amounts of antilag and you need the ability to quickly change the turbo every handful of stages.