Gas engine fuel mpg?

A related comment: Fuel is my no means the most expensive part of RVing though it may seem like it after 2 fills on a long day. Even more true is that the difference of a few MPGs is almost of no consequence. The big expense is the RV and it's depreciation plus upkeep, repair and fees.

If I remember it right between 2012 and 2018 the gasoline become less gasoline and more ethanol.
Same with diesel having 5 to 20% of bio in it.

Morsnow, it looks like the older you get the heavier your foot or you feel like you have less time to get there. Just saying, lol.

Morsnow , to what do you attribute the loss in mpg from 2012 to 2018 ?

12-13 mpg
2014 F350 SCLB SRW 4x4 6.2 V8 + 2017 Northstar Arrow
mostly long range at moderate speed (55-60)

I have a 2015 Ram 3500 6.4 gasser and with the Ascent 85 RE camper on we get 8.5-10.5 mpg. With it off 13-15 mpg.

We have a 2016 Ram 2500HD, 2WD Crew Cab with the 6.4L Hemi. In 2017 we traveled from Georgia to British Columbia and Alberta and back stopping at Glacier and Yellowstone National Parks. We were carrying a fairly light Adventurer 80RB coming in around 2,400 lbs as loaded. Covered about 8,650 miles and averaged 13.8 mpg hand calculated. Over one stretch of 300 miles with a tail wind we achieved 20.2 mpg while the lowest daily average was 12.8. This was driving sedately between 55 and 65 most often with the occasional 70 mph for short periods of time.

2005 8.1L with a ~4K lb basement type camper. I’ve only checked the mileage a couple times, with a mix of freeway (65-70mph) and 2-lane highway.

About 8.5 with camper only.
About 8 with a 2k lb cargo trailer in tow.

Again, limited sample and was doing nothing to maximize mileage. Vacation time is more valuable to me right now.

2012 GMC 2500 6.0 Gasser 3:73 Gears, 2014 Wolf Creek 850 (Purchased July 2013), and a 16' Aluminum trailer with a SXS

I have every gas receipt since the truck was delivered on April 13 2012. 90% of these miles are with the camper and trailer with SXS. I'll be calculating this past years (April 13 2018-2019) mileage after the trucks birthday.

2017-2018
4,332 Miles Driven
424.87 Gallons of gas
10.19 MPG
$1,219.25 Total gas expense
$2.86 Avg per gallon

2016-2017
3,786 Miles Driven
378.81 Gallons of gas
9.99 MPG
$1,961.45 Total gas expense
$2.53 Avg per gallon

2015-2016
4,572 Miles Driven
432.11 Gallons of gas
10.58 MPG
$1,133.19 Total gas expense
$2.62 Avg per gallon

2014-2015
4,500 Miles Driven
421.42 Gallons of gas
10.67 MPG
$1,515.11 Total gas expense
$3.59 Avg per gallon

2013-2014 (camper Jul 2013)
6,557 Miles Driven
581.33 Gallons of gas
11.28 MPG
$2,222.86 Total gas expense
$3.82 Avg per gallon

2012-2013
7,058 Miles Driven
537.22 Gallons of gas
13.13 MPG
$2,133.05 Total gas expense
$3.97 Avg per gallon

Can't use me...I'm DRW and old.....lol

1990 F350 dually
460 EFI
ZF-5 manual
4:10 limited-slip

Empty at 55-58 mph nets 12.5-14 mpg highway and 10 mpg around town

With the S&S TC @ 10,500lbs at 55-58 mph nets 9-10.5 mpg highway and 8 mpg around town.