In testing the 370Z on the dyno, its becoming apparent that the 370Z is going to have issues with oil temperature. With simple dyno testing which only involves wide open throttle for a few seconds, the oil temperature rises to the 260 degree range. In bumper to bumper traffic and even in normal semi brisk driving in the mountains, the temp soars into this range. Note that this isn't even fast driving, just normal driving.
In my experience in motorsports, bearing load carrying capacity starts to get affected negatively when oil temps get above 260 degrees. The 370Z seems to run in the range frequently which amazes me. Now when putting around on the street you are not likely to hurt stuff but if you do the slightest bit of extended wide open throttle driving, things might start to get seriously bad.
I now feel that an oil cooler is mandatory if you do any sort of track day or drive hard in general. Even sporting type driving will probably put the temperature up high. I think frequent oil change intervals using a high quality synthetic oil is going to be mandatory as well, even for causal use.
I have a few theories on why the oil temp is so high on this engine which I will probably do an article on in the magazine section in a few days.