Ok. I just hauled a 7K trailer up the hill to Genesee (same test as before) but I don't have the cooler hooked up yet (LB7). I wanted to get a base line. I know 7K isn't much, but I think it's about average of what most haul and it's a good line between aerodynamics, and weight. Slide in truck camper and large 5th wheels seem to have a hard time with this because of the crummy aerodynamics (5th wheels even more so because more weight is added). A hard side slide in camper with a heavy boat or trailer behind it represents this as well. Mine was a boat and trailer combo to the tune of 7K even. Here the break down.
Test temp was
60-65*F outside. Held the speed limit (65mph) and kept EGTs at
1250*F or bellow for most all the trip. Just standard cruising down the fwy I was sitting at
200*F oil temp almost all the time once the temp was up in the truck. Coolant temps were
175*F (standard for me). By the time I got to where the hill really starts to go up, I was sitting at
226*F and oil pressure at the journals was
33psi at
2K rpm. The coolant temp was now at
195*F. The oil temps climbed pretty rapidly but the coolant temp stayed at
195*F for the duration of the test. Temps dropped to high
50s out side by the time I got to the top of the hill (Genesee turnoff), and the oil temp was at
243*F and oil pressure at the journals was sitting at
31psi at
2K rpm. Idle was sitting at
13.5psi at this temp. The kicker is this. At
182*F oil temp my pressure is no less than
44psi at
2K rpm at the journals. This is a
13psi drop.
. Also this hill is by no means in the same league as the West side of Vail pass or the West side of Eisenhower tunnel (bit of a drive for me round trip). The temps held well at the
240s. I had to turn up the DSP5 a level to get it to go much higher, but boy did it when I applied the power. I'm not going to include this info since we shouldn't be towing at this power level but was a testament to me of how hard I've been on it in the past when passing vehicles on the grades. Just remember, the temps were low today. I have no doubt it would have seen north of
250*F oil temps if it would have been
80-90*F outside.
On edit: This was performed using Mobil Delvac 1300 15w-40. I will also be repeating this test with the cooler hooked up and the same oil and then doing it again with Schaeffer 9000 5w-40 full synthetic to see the differences. I'm up for any improvements we can have for the life giving fluid of the motor.
