^ Foxspeed is right.. I ran quite a large oil cooler on my Nissan 200sx and with a thermostatic switch it worked perfectly.
Most quality oil would be OK up to and around a constant 130oC, some more pricey oils will be OK at 150oC.
I seem to recall with a huge cooler in place it kept the oil at around 110oC on and off track, without it I was in the 140's... So, I guess if you do regular track days, it's worth looking at.
Rich