First extended trip with 5th wheel

tim665214 wrote:
2016 Jayco Eagle HT 29.5 BHDS. Approx 10K GVWR. Tow vehicle is 2016 Ford F250 6.7 Diesel Crew Cab lariat. Coming from North of Fort Fort Worth to San Antonio via 281. For anyone not familiar with this route this is right on the edge of Texas Hill country. So not flat, but not exactly mountain terrain either. It was me, my wife, 15 year old daugther and her friend as passengers.

I was really hoping to get close to 12 mpg, but overall I averaged right at 10 mpg. Does this seem about right. I also noticed that when I had cruise control on (65 mph) that on the steepest hills it would always shift down to 5th gear, and 2 times it shifted to 4th. My truck had no problem holding speed, but it just surprised me that it had to shift down like that. When I wasn't using cruise control, it never had to shift into 4th, but it still shifted into 5th quite often.
Is this what everyone else is noticing who has a similar setup?

We've driven through the TX hill country a number of times. For those who haven't, the TX HC is comprised of many miles of repetitive, rolling hills. Depending on the truck and load a truck may downshift on nearly every hill. IMO, that's a lot of unnecessary wear, and tear on the tranny. We always lock out 6th, sometimes 5th, whatever it takes to keep the tranny from downshifting. Doing so may sacrifice MPG's slightly, but IMO a fair trade-off to prevent unnecessary wear and tear on the tranny.

We also turn off cruise control in the hills. The cruise control, in its all-out effort to maintain the exact speed, uses more fuel regulating the exact speed/power. When that fails it won't hesitate to force a downshift---using even more fuel. We get better MPG's with the cruise off. It's easy to prevent a potential downshift by simply rolling off the throttle slightly on a hill. You can make up for the slight loss in speed on the downhill side.