Looking for the “sweet spot”

[Thumper]

I’ve been playing around with my speeds while traveling to find my sweet spot speed for fuel mileage. This big square box on wheels isn’t exactly aerodynamic! I’m running close to 12,000 lbs. and it’s a dually, so I don’t expect to make Biden’s tree-hugging greenies happy, but I’d like to keep my wallet as happy as possible.

Yesterday, I ran with the cruise control set at 62 mph when in the highway. We did some around town driving (did a bit of shopping, checked out a couple of “touristy” things, made some fuel stops, etc) plus we ran into a few traffic snarls through the cities we passed through. Then we hit two road construction areas where they shut the Interstate down to one-lane, so there was a lot of the typical stop & go routine with traffic backed up for miles. I still managed to squeeze out a 16.6 mpg average on yesterday’s run, but these things can supposedly do 18. Of course, that may be downhill with a tail-wind, who knows? (I’m also running prolly 500-600 lbs. overweight). Today is another day and I’ll “maybe” make some adjustments, but I’m not really sure I want to get under my present 62 mph cruising speed. I’d be happier at 70, but with the crazy price of fuel these days, I’m happy to compromise.

(Lower left is cruise setting, the 54 is my average mph)

https://uploads.tapatalk-cdn.com/20220910/e2288abaa1e71688c642b0d9c5d69e95.jpg

[BarryBobPosthole]

That fuel mileage sounds pretty darn good to me for a unit like that. What kind of tranny? Six speed? I know when I’m pulling boat if I set the cruise it’ll sometimes hunt gears in some terrain and that drops the mileage a bit. Even with tow/haul turned on.

I do the same thing as you on road trips. I’m trying to find that sweet spot for gas mileage.


BKB

[Thumper]

It’s a 7-speed P-hole and we climbed through the pass in Tennessee where the simi’s were in the right lane with flashers and doing 20-mph. There were quite a few gasser motorhomes in the line, but tbh, I couldn’t even tell we were climbing. That right there sold me on the turbo diesel. Heck, it’s just a dinky 3.0 liter pumping out a whopping 188 hp, but man-o-man, the torque is where it’s at I guess. I’m old school where horsepower is master, but this thing is teaching me some things. The tranny is slick as butter and I can’t even tell when it shifts. If I didn’t watch the tach, I’d never know what it’s doing. I’m very happy with the performance so far … and it concerned me at first. I mean, come on, a 12,000 lb box on wheels with 188 hp? Really? I think I’ve been converted … educated and enlightened. Who says you can’t teach an old dog new tricks?

[Trav]

We talking about the rig or you being overweight, lol