Ok back from the mileage test run.
Conditions were:
53 degrees (F)
Interstate 5 from the Aurora Flying-J Truck Stop RV pump #26 to center of town in Lebanon Oregon, and back. 118 miles round trip.
Both vehicles used the same pump (same ground angle) before and after the test run and both were filled just till bubbles would not come up to the fill neck.
1st test vehicle: 2008 M1079 A1R with C7 @ 370 HP / 931 TQ with ECO Hubs.
2nd test vehicle: 2003 M1078 A1 with 3126b @ 330 HP / 870 TQ with stock reduction hubs.
1st vehicle in the lead with cruise control set at 55 mph.
ECO Hubs: 11.58 gallons used.
10.189 MPG
Stock Reduction: 17.12 gallons used.
6.89 MPG
ECO Hub fuel economy improvement of
3.299 MPG
I did the math - at that savings the hubs will pay for themselves in 3,203 miles. And the reduction of wear and tear on the drivetrain and the other benefits I will try to outline below are incalculable.
Other notes:
Non ECO Hub vehicle engine was screaming at redline to keep up and the radiator fan ran every 2 minutes (we timed it) once it got up to temp. The ECO Hub truck never ran it's radiator fan the entire day (including a high speed run later in the day) of driving around 150 miles.
ECO Hub truck is extremely quiet in the cab. Engine feels like it's VERY happy. Entire drivetrain feels like it's happier. The hubs are cold or barely warm to the touch.
In testing on a very familiar hill near my house where my truck would previously only do about 37-38 at max effort, the ECO Hubs flew up the hill at 45 and I had to back out of the throttle.
Acceleration is better - my truck was always fast off the line with the 370 HP map but now it's fast AND smooth. The 2-3 shift is more like the other shifts.
On the C7 trucks (and I suspect this will be the same for the 3126b trucks) the speedo is driven by the engine ECM and since this also controls exhaust brake minimum engagement speed, cruise control minimum speed and logic, etc - once I programmed the pulses per mile from 62,618 to 31,309 everything simply worked. Speedo, cruise, exhaust brake, etc.
Transmission behaves exactly as it should. 7th shift doesn't happen till you get a bit over 60 MPH. When coming to a longer grade on the freeway the cruise would lean into the throttle very gently and then the trans would downshift to 5th at times to maintain 55 mph. It works perfectly.
After the test on the way home I dropped the hammer on it (not speed limited by my tires - they are new), and hit 85+ mph. I backed off. It had more in it.
BTW the C7 MMDC canbus guage tops out at 80. I was definitely going faster. Not sure how much faster - I was watching the road
For the record my truck is very smooth at 80. It's a bit unnerving going that fast in this machine. You can also see where my temp gauge is sitting - that's where it was all day. Meanwhile the poor 3126 truck was cycling the fan every 2 minutes.
The fellow member who owns the M1078 used in this test was so excited by the results he ordered a set on the spot.
Conclusion - IDK how many sets he has left but GET THESE NOW! Throw the reduction hubs in the nearest lake. F that mess they are worthless.
