is a smaller water cooled oil cooler better than a traditional air style?
 

Just wondering what everyone recommends?

No. We Nissan techs call the one on the 350Z the "oil heater".

It depends on the application. OEM liquid oil coolers are great at getting your oil up to temperature faster since they utilize your coolant. Coolant pops up to temp faster then your oil. Remember, cold oil is not good either and causes extra wear and tear on internals. To a certain extent, they are very efficient as oil coolers as well. When you get into extreme situations, that's where this type of cooler is probably less efficient then a traditional air cooled system. I honestly would consider finding an OEM liquid cooled cooler for the tib since its not a track only car, would help pop my oil temp up faster at startup, and I would still benefit from the cooling it would do for the spirited driving that I do with my car. Your application may be different and need a more extreme approach to oil cooling.



Real estate is getting scarce in my engine bay! But, I honestly would want both. You would need a modified high flow oil pump to accompany it, but an OEM liquid cooled system to pop your engine temps up to normal faster, and a thermostatic switch to send oil to a super efficient radiator style when you take the car to its limits. I think this would be the end all of oil temperature control!

I had an air to oil cooler and it would keep the oil too cool unless you have a good oil t-stat. Milne was built in 160F and anytime the ambient temps wee below 50F that is what the oil ran, too cold IMHO.



I put a Ford SHO oil to coolant cooler on mine. It threaded right into the OEM oil filter adapter but is taller than the OEM one and the filter will stick down too far. So I also have a remote mount oil filter for that. I wish I could find a remote mount that took the metric threads and I would mount the cooler with the remote filter. But they only come with the 3/4-16 threads unless you want to spend the big bucks.



But it is great in what driving I do. Summer time with AC on and +90F temps and 75 mph interstate and the oil was under 210F. In the winter it runs about 170-175F. Oil heats up withing 5-10 miles even below freezing.



You need a better than OEM radiator for good cooling in the summer.

Neither is inherently 'better', they're just heat exchangers after all. Like intercoolers though, air-oil is cheaper for the same cooling capacity, so water-oil is really only needed when you have a cramped engine bay and need to put coolers out of the way.

For everyday driving the water/oil is definitely better assuming you radiator is up to the task. For the track you probably need both and a good radiator.