Hey all,
As I've mentioned in other posts, I've noticed a drop in fuel economy that I thought coincided with my changing from P265/70R16 Coopers to P265/75R16 REV02s. I've dropped from 19/23MPUSG to about 14/17MPUSG. So pretty significant.
I'm wondering if there is a deeper problem here. I have the Superchips Cortex, and one of the features is a real time display of J1939 parameters such as Engine Coolant Temp, Advance angle, Vehicle speed, etc etc, and also includes a parameter for Calculated Engine Load %.
Normally, when cruising on the highway at 65mph, the Engine Load shows about 50-60%. I mentioned this to one of the engineers at work, and his eyes nearly bugged out of his head. He said he'd never seen anything over 25% in his experience. However, the truck seems to be running great otherwise, no weird shifting, no hesitation, and I pull my massive camper with it with seemingly no issues.
Does anyone else out there have a Cortex or other tool that tells them what the ECU is calculating for engine load? Or does anyone know what the normal value of this parameter would be?
I tried a few things on the way home today. Engine load at 65 MPH was 50-60%. When I clicked off the O/D, engine load dropped to 40%. When I downshifted to 3rd, it dropped even more, to about 35%.
Does this seem normal?
Comments appreciated. Wondering if I have a binding transmission/diff/transfer case. Like I said, no issues apparent in driving, seems normal in all ways, acceleration is great, power is great. Reverse is fine.
Thanks!
t