I think you are right. Jeep runs the test, it passes, the number gets advertised. Simple as that. Truthfully I assumed that the specification would follow a bit closer to what an average user would expect/try to utilize, but that is very subjective I suppose. Having owed several large trucks...
While I agree that using the most delta T is ideal, oil coolers have advantages that radiators do not, and routing airflow properly is key to cooling, a horizontal oil cooler on top of the hood? C’mon.. Nobody is doing that, nor should they have to.
So far, the limited testing indicates that...
If the fan is running at highway speed to assist in cooling, and the size is enough to dramatically counter the inbound air, then a big area of low speed air is being created in/around the heat exchangers. Further strain, and thus heat, are also being generated as the fan motor struggles to...
For those curious.. I was looking at mine yesterday, and noticed it came with a 940w fan. I am 99% sure that previous models had a ~850w on the trailering package, and ~640w on a standard diesel/gas.
Clean the area thoroughly with some dish detergent one evening. Check it the next morning or right when you get to work after a commute. Start working your way up. BTW, your dealership could easily have done this.
It is crazy that even with the full grill removed, there is not enough cooling to be had with the stock heat exchangers. I wonder if it is a hot air evacuation problem, maybe the exchangers are not sized properly, or as one poster mentioned, in order to better complete combustion higher general...