Community Forums

Ludmilla · 07-05-2019, 11:35 AM

We set the cruise around 62 mph. No more than 65 mph. We get 7.5 miles per gallon including fuel we use for the generator. We run the generator about 45 minutes under load on each trip. We drive out west - lot of hills. We have a Cat C7 350. We have been calculating our mpg for years and it is consistently 7.5 mpg over a year period.

Mainer1 · 07-05-2019, 11:47 AM

I think you got a number of honest answers, but, unfortunately, not from the seller. Gas class A units will get between 6 and 9 MPH depending upon conditions and speed -- I do 7.5 to 8.5 at 62 MPH towing, unless there is lots of wind or hills, with my 35' class A -- Chevy 454 and Allison trans. Honest diesel owners will tell you a mile or so better than that. The key is to try to be consistent, keep tire pressures correct.

Korryp · 07-05-2019, 11:56 AM

I’ve got a 1997 Bounder Turbo diesel with a chipped Cat C7. I average 8mpg towing and 9.7mpg doing 68 mph.

RV Tinker · 07-05-2019, 12:22 PM

Best was 11 mpg but was going down hill for the trip. Coming back the same route got 8 mpg. Worst ever was going from Saint George Utah to Las Vegas, 5.5 mpg, Had a 40 mph (or worse) head wind the whole way :( .
29 ft, 2004 MiniWinni, V10, Subaru Forester toad.

Danesrus3 · 07-05-2019, 01:51 PM

We have a 38' DP with toad- 60-65MPH wo 70-75MPH avg 8.7 to 9.MPG

SStravels · 07-05-2019, 01:59 PM

We have a 2014 Forest River Legacy 340KP (36') with a 300 HP diesel. I have checked it on several long trips and we get from 9.0 to almost 12 mpg with a toad. Last trip was to Elkhart to the factory to have the slide floor replaced. See my post on the rotten slide out floor. On the way back across Ohio I got 10.5. After going through West Virginia it dropped to 9.0. I thought the 300 HP would not be enough power, but I am very happy with it. I cant go over 65 because of the toad speed limits being an automatic. I set the cruise at 63 and enjoy the ride.

markgott · 07-05-2019, 07:07 PM

42 ft Tuscany with dolly towing, we average 8 mpg with cruise control set to 65 mph. Diesel consumption would be titch higher except for AquaHot using fuel to heat.

bmoran · 07-05-2019, 07:27 PM

While on a trip to CO and back a few years ago, I averaged 7.5 mpg in my '94 34' tag axel Aerbus. I like to run with the trucks +/-.

JRI · 07-06-2019, 06:21 AM

I got 25mpg on my last trip doing 75 to 80 mph. Then I woke up and realized it was only a dream.

I don't think you'll see 12mpg unless your route is all downhill.

Jchemie · 07-06-2019, 08:20 AM

I can cruise at 75, but from my experience 67-68 mph gives me the best fuel milage and least number of the “you’re #1“ finger from the road rockets. Only getting 8 mpg? That’s normal. Your former owner must have got his numbers going downhill with a strong tail wind. I get 8.5 when I’m solo, that is, not towing the toad. 2004 Holiday Rambler Neptune DP 35’, aka a 12 ton brick.

J. W. Hyde · 07-06-2019, 09:54 AM

Quote:

Originally Posted by Farkey

Being new in the RV world I have numerous questions and here is my latest.

At what speed do you people usually cruise on an interstate highway?

I travel at about 60mph because the previous owner said that was the best speed for fuel economy and he would average 12 MPG on a trip.

On my last trip of just under 500 miles, I tried to cruise at 60mph and at the end I got 8.2 MPG. Now mind you that was through the hills in the Finger Lakes, but still getting almost half of what he did.

Unfortunately, I can't ask him any questions because he passed away just after selling me the rig.

So I will be very appreciative of all what you have to say on this subject.

Thank you

We cruise between 62 & 67 mph with as close to 1600 rpm as I can get--03 Phaeton DP with turbo charged cat. Gets us close to 10 mpg--depending on flat or mountains---been doing it for 15 years and very few mechanical problems at just over 130,000 miles.

Iancmrn · 07-06-2019, 10:08 AM

Quote:

Originally Posted by docj

My MH has a Silverleaf in-dash display and I use it as a consistent reference for fuel economy. I realize it isn't perfect, but using the same device for all comparisons provides for a measure of consistency. Having said this, the Silverleaf almost always shows fuel economy that varies between ~7.8-8.8 mpg depending on conditions and speed.

For example, in Canada with a 100km/hr (60 mph) maximum speed and cruise control engaged we were easily able to achieve an 8.6 mpg on relatively flat terrain. In the US I typically cruise at ~63 mph because it allows my transmission to shift into 6th gear while staying below the 65 mph tow limit for my CR-V. At 63 mph I get roughly 8 mpg. This is with a 425 HP C12 pulling a combined load of ~37,000 lbs.

I am usually running at 65-70mph and I am getting around 15mpg but mine is a 26' Class A on a Mercedes Sprinter chassis and a Mercedes V6 turbo diesel. If I slow it down we sometimes get up tp 19mpg. We love it.

promaster18 · 07-06-2019, 10:20 AM

Around 24 -28 mpg at around 65 -75 mph on our v6 gasser

Excellent mpg and good retirement cruising speed and we can park anywhere

cekkk · 07-06-2019, 11:12 AM

Years ago when I still believed my diesel should be giving me 15 mpg instead of 11, I held it to 55 traveling a 775 mile trip we'd taken a couple of times with the same setup.

I don't remember the exact mpg anymore, but it sure was not worth losing those 7 miles per hour for two days on the interstate.