[SentraSE-R]

Following is a terribly uncontrolled comparison, but I'll toss it up for illustration and discussion. I drove four of us to dinner 75 miles away, leaving from Bryce Canyon National Park at 8000' elevation and going to dinner in Boulder, UT. The extra 450 lbs of passengers in my 2200 lb. xB is a 20% weight increase. The drive has a final 1300' elevation drop to Boulder, but that doesn't tell the real story. There are 12 and 14% grades on the route that necessitated shifting to second gear to climb them. By the time I reached Boulder, I had a 50 mpg trip average per the Ultragauge. At the end of the roundtrip, back in the park, I'd averaged 42.7 mpg. I had to run the AC from time to time, and the lights on the entire trip back. I tried my usual P&G (the passengers were all interested in seeing how I got 50 mpg on the trip out).

Three days later, I repeated the trip, without the passengers, and didn't use the AC or lights, so it wasn't a very good comparison. Nonetheless, the results were much better in both directions without the load. I averaged 55 mpg to Boulder, and 47.5 mpg for the round-trip, about 5 mpg better in both directions. I averaged 140 mpg the first 7 miles to Tropic, UT, and an amazing 71.9 mpg for 48 mpg to Escalante, UT.

I probably could have improved my loaded mpg if I'd been able to concentrate better, didn't run the AC or lights, and learned to compensate for pulsing with the additional load, but I doubt I could have improved it 5 mpg in either direction. The extra load simply overwhelmed my 108 hp. The heavier load meant I simply couldn't accelerate at my usual 83 load. 83 on the Ultragauge had me barely maintaining speed, and I had to mash it into the 90s load range to accelerate on far too many of my pulses.

Interestingly, I still had to drop to second gear to climb the steepest 12% and 14% grades, but there were a lot of hills I climbed in 4th and 5th gear solo that had me a gear or two lower with the extra 450 lbs of passengers (one 230 lb male, one 90 lb female, one 120 lb. female, clothing).