I don't have an RV at this moment, but here is the full unloaded history of my truck.
Avg MPH/Odo/Lie O Meter/Hand MPG
0 / 361.0 / 17.8 / 16.97
21 / 737.0 / 17.5 / 15.64
41 / 1,180.0 / 20.2 / 18.96
29 / 1,610.4 / 19.2 / 18.24
30 / 2,068.2 / 18.9 / 18.40
44 / 2,331.3 / 21.1 / 20.00
29 / 2,716.2 / 18.6 / 17.78
24 / 2,909.0 / 18.0 / 17.56
49 / 3,174.6 / 22.0 / 21.66
32 / 3,597.2 / 19.8 / 19.03
32 / 4,021.1 / 19.1 / 18.36
31 / 4,449.6 / 18.7 / 18.07
30 / 4,846.2 / 18.1 / 17.97
37 / 5,322.4 / 20.5 / 18.74
35 / 5,719.7 / 19.1 / 18.96
34 / 6,064.5 / 19.3 / 18.94
39 / 6,544.7 / 20.2 / 19.94
32 / 6,928.9 / 19.1 / 18.43
40 / 7,404.9 / 19.6 / 19.97
27 / 7,748.6 / 17.7 / 17.24
31 / 8,067.0 / 19.1 / 18.20
31 / 8,525.1 / 18.7 / 18.21
30 / 8,934.3 / 18.7 / 18.34
29 / 9,363.8 / 18.6 / 17.98
28 / 9,768.8 / 19.4 / 17.91
28 / 10,152.0 / 18.6 / 18.33
30 / 10,512.4 / 19.7 / 18.44
36 / 10,934.7 / 20.9 / 21.02
Most of my 18 mpg runs averaged between 60% and 80% city driving. My 21 mpg runs averaged between 0% and 40% city driving.