[Qmulus]

Originally Posted by JFP in PA

One word: efficiency. Because liquid heat exchangers are more efficient at transferring heat than oil to air units, they can be much smaller. To use an oil to air unit that has the heat transfer capability of an S cooler, you would need one that would be more than three times the size of the oil to water unit, and then the question becomes where would you put it so it got enough air flow over it, keeping in mind that the oil pump in these engines preclude running it at the front of the car. People seem to forget that there is often a 30-40 degree temperature differential between the coolant (even when hot) and the oil, so there is plenty of temperature difference to accomplish cooling the oil.

^ What he said. Porsche obviously knew about air to oil coolers. They used them for decades on the air cooled cars. The thing is, it is quite easy to add an appropriately sized oil to coolant heat exchanger and then design the coolant system to work with the thermal load imposed by both oil and coolant. It works for the 911 Turbo as well and if anything would need lots of cooling, a turbo car would.