08 Coachmen Elite
 

08 Coachmen 40" 360 horse Cummins 8.3 ISC with Bully Dog Tuner(@415 hp)
7.2 pulling trailer 65-70 9.2 mpg running 58 mph no trailer.

MPG
 

My 2004 Country Coach Intrigue, 42 ft. with tag axle, weighing in at 43,000 lbs including the toad, got 5 mpg. Cruise set at 75 mph on open interstate, unless in the hills. Most other roads were posted speed limit or below, especially in mountain areas.

MPG
 

40 Ft. 2003 Travel Supreme
400 Cummins ISL
2018 Chev. Phoenix automatic
63 mph on cruise
8+ miles per gallon

Big 2 factors are you going full time or like me only + - 15 k a year If full time yes diesel but cost of operation is hi and the more miles you pound it gets better, Gas jobs like mine a 2002 adventurer 32V with a workhorse chassis and a Allison automatic,8.1 gm gas job does me fine + - 7 mpg cost factors a lot less as a diesel as very good engines but very costly to fix if you are driving low miles every year. I am a retired trucker with over 4 million miles under my belt ,So I guess my question is if full time 40' plus nice but part tine personally 32-36' is all you need with out big @ss aches as to maintain your new RV.

2001 Newmar Dutch Star 3858 CAT 3126B 300HP FL chassis. Around 8 mpg MAX w/Cruise set for 62. No tow. Mostly flat Interstate.

2013 Thor Palazzo, Cummins ISB 300/Allison with 46000 miles on it, pulling a full sized HD Deisel Silverado, flat hey 10-11.5 MPH. Amazing!, drops down to 9.5 with hillis.

Diesel pusher milage
 

2001 Monaco Cummins 350 hp Allison trans. I get around 8-8.5 mpg. It doesn’t care if I’m towing anything or not. I use the cruise control as much as possible. When it’s on cruise, it has more power climbing hills. I just let it go!

2009 Monaco Diplomat 38', 400 horse Cummins pulling a 1999 Dodge Durango and long trips, 7.3-8.1 depending on how many mountains.

I have 2007 National RV Tropical LX T350 which is 36' long with Cat engine. Mileage computer display shows 8.8 to 9.0 depending on terrain but mostly at 8.8. Coach is comfortable and well built. National no longer in business but common parts and components are available.

Mpg
 

2001 Monaco Executive, 500hp Cummings. We went coast to coast last year, mountains, flat lands, snow and sun...you name it. We were towing 5x8 enclosed trailer. We averaged 8.6 mpg over the two month trip and covered 8600 miles.

2015 Fleetwood Discovery 37ft.
Cummins 380HP
If I drive ~60, i can get 10.
But that drops off rapidly when the speed increases.

DP fuel mileage
 

Have a 2007 Fleetwood Excursion 40X, 360 hp Cummins Lincoln MKX toad, run 65 mph as law allows. Average around 7-7.5 mpg depending on terrain. No DEF and regen every 2,000 Miles.

Diesel Mileage
 

2005 Travel Supreme 40' with 400HP Cummins

Flat towing with Saturn Vue toad (Carolinas, Florida) we get 10mpg.

Driving through the mountains (hills?) in New York and Pennsylvania it's more like 6mpg.

Overall I always use 8mpg for any trip calculations and it's usually bang on!

JOHN

2006 42' Gulfstream 450 Cummins, overall average 6.3.