Originally Posted by ka9mnx
If your cooling system is working the engine will not know, or care, what the ambient temperature is. I would agree with you if your coolant system couldn't keep up.
Oil temperature and coolant temperature are not directly proportional. Track day enthusiasts regularly see this [as do Middle East motorists] . The 278 degree oil temperature in the quote below shows just how out of control oil temperatures can get even with an OEM oil cooler. I understand the temptation to think that oil temperatures will be managed by the oil flowing over relatively cooler components. The reality is that oil temperatures can spiral out of control in high ambient temperatures, engine destruction can and does result.
It's good to remember that oil transfers heat much more slowly than water. Oil temperatures can and do continue to rise under some circumstances.
Quote: "To be fair, it was pretty hot at the track, about 28 C (84F) on the hottest session, and I was pushing the car pretty hard. Sessions are 20 mins, and I was near the end of it. I checked the performance pages display and my engine oil temp had got up to 137 C, or about 278 Fahrenheit At that point, I backed off and did a cooldown lap. The car had no warning lights or limp modes or anything like that, still had plenty of power, but that scared me a little. The coolant temp stayed pretty normal, I don't think it exceeded 105 C"