Your best mileage, class A diesel.

[WILDEBILL308]

My house gets better milage than your house. LOL
Bill

[Maladjusted]

Hit the fuel stop again today.. 686 miles, 73.2 gallons with 7 hrs of generator use while traveling.... So I figured 5 gallons for the gen? So 68 gallons used for 686 miles. 10 mpg. Not bad for towing my wifes 5600 lb Tahoe.

[RickO]

Originally Posted by Maladjusted

Hit the fuel stop again today.. 686 miles, 73.2 gallons with 7 hrs of generator use while traveling.... So I figured 5 gallons for the gen? So 68 gallons used for 686 miles. 10 mpg. Not bad for towing my wifes 5600 lb Tahoe.

Very impressive!

Color me jealous.

Rick

[Maladjusted]

She's no barn burner... But I can maintain highway speeds on the minor hills here on the east coast.

[Alan JS]

Originally Posted by Stanmawyer

Trip from Dallas, TX to Ocean City, MD

American Heritage 45 ft. C15 Cat Acert engine. 600 hp, 1950 ft/lbs torque
12.5 KW Generator running constantly, powering 3 roof air conditioners, fridge, etc.
Towing 4900 lb Jeep Commander Limited
Average speed 68 mph
Crossed 3 mountain ranges ( went up and down on cruise control)
Mostly highway driving

5.6 mpg.

I'd love for it to be better, but I do love the hill-flattening torque of my big Cat!

Wow you better hope you pass an awful lot of diesel stations along the way or else your diesel pusher is going to become a diesel "pushed"
Even with a solid chassis I find that 68-70 mph tends to get me in trouble. I don't like passing other trucks and it only takes a split second on inattention at 68 mph to end up in another lane.
Our mpg and wind resistance suffer in the higher 60's.

I also leave it on cruise control to rest my leg and improve mileage.we keep our pets close to the cabin so usually the dash AC is sufficient. I heard from our mobile tech that running the AC 's on generator was better mileage than through the dashboard.
Is that true? I always thought that since the engine was already on the AC didn't subtract much fuel/mileage.
Which is it?

[condor918]

I have a 2011 Holiday Rambler Neptune with a 360 ecummins. On a trip from Albany NY to Litchfield ME using I90/I494?I95 (338 miles) I used 30 gals. of fuel. 11 MPG. I weigh in at about 35000 lbs. Tha's about the only good thing about this unit. Electrical probs galore. but mileage is GREAT.

[Piker]

Originally Posted by Alan JS

Even with a solid chassis I find that 68-70 mph tends to get me in trouble. I don't like passing other trucks and it only takes a split second on inattention at 68 mph to end up in another lane.

If that's true, then you must have mechanical or tire issues? Our old rig tracks straight down the road at 75mph with no problems. Just feels like your driving a truck or car... with a few extra rattles from the inside. We had some radial pull at one point, but a tire rotation solved that problem quickly.

Originally Posted by Alan JS

I heard from our mobile tech that running the AC 's on generator was better mileage than through the dashboard.
Is that true? I always thought that since the engine was already on the AC didn't subtract much fuel/mileage.
Which is it?

I have heard that too... I can't find any solid test data on the net that says exactly how many hp an auto compressor will use, but I've been reading reasonable guestimates that they use around 5-10hp. That might not seem like a lot, but I guess it would depend on how many hp it takes to push your rig down the road at any given mph. Your engine might be 300hp, but say at 60mph it only has to produce 100hp to get you down the road... if you add a 5 or 10hp draw to the engine, that would be a 5 or 10% increase in fuel usage... I think... really I'm just guessing.

It's hard for me to believe that a compressor run right off the engine would be less efficient than a compressor that is run "indirectly" off the generator's engine through a generator head... but who knows? Most of the evidence we read about on the net is anecdotal... doesn't mean it's not true though.

Our dash air hasn't worked since we got the RV... so I have no first hand comparison. I do know that running our 7.5kw diesel generator to run our 2 rooftop units drops our mileage about .5 mpg or so when traveling on the interstate.

Since I doubt that the dash air in our rig would even remotely be able to keep up by itself, I have been tempted to try and retrofit an electric motor and compressor to run the dash air off of the generator along with the rooftop units... might not be worth it now that I've put direct air dumps in the rooftop units. They seem to work pretty good on their own now.

-cheers

[dajudge]

If you get 10 or more mpg, you must be travelling downhill all the way, possiby with the engine not running.

[Piker]

Originally Posted by dajudge

If you get 10 or more mpg, you must be travelling downhill all the way, possiby with the engine not running.

We get a solid 10.5-11mpg... hand calculated over a 6200 mile trip out west and back. It was not downhill both ways. We ran our engine...

If you're getting less than 10 mpg, then your RV is probably heavier than 10 tons gvw and/or possibly burns gas instead of diesel. Mileage depends on many factors, but for someone to make a blanket statement that no one can get more than 10mpg is simply evidence that they are uninformed about every combination of body-style, chassis configuration, and drivetrain combination that exists. No big deal... who ever could be that informed? ...so what's wrong with taking people at their word sometimes, even if it makes you feel uncomfortable that you don't get as good a fuel economy as you would like?

Granted, some people do make mistakes when calculating their mileage...

It's all good... those who have the $$ to be carefree about fuel costs should let those of us who make fuel costs a consideration feel free to worry about our mpg without judging whether we should or shouldn't worry... and of course those of us who are trying to eek every last mpg out of our rigs should likewise let the ones who don't care just enjoy their blessings in life. I'd love to not have to consider the price of fuel... but it's just not where I'm at right now. I'm still having fun though... and the family too.

-cheers

[t55watson]

Originally Posted by dajudge

If you get 10 or more mpg, you must be travelling downhill all the way, possiby with the engine not running.

I got 10 mpg once. Then I found my math error. Oh dumb me!

[Chaffeekid]

Most recent trip from Southeast Missouri to the Kankakee Illinois area and back, 11.287MPG. Miles driven/gallons used, towing my full size dodge ram.
Engine 5.9 Cummins/Allison transmission, 4 speed with overdrive.
Never over 60MPH, power/economy switch in economy position.
Jim

[Maladjusted]

Originally Posted by dajudge

If you get 10 or more mpg, you must be travelling downhill all the way, possiby with the engine not running.

Huh... Interesting comment.

686 miles, 73.2 gallons with 7 hrs of generator use while traveling.... Full fill, ran to Atlantic City and back to Richmond, Va full fill again.

So I figured 5 gallons for the gen? So 68 gallons used for 686 miles. 10 mpg.

Would you like me to video the trip and show you the receipts the next time I travel?

Oh and btw... My rig is 28k lbs with out the toad. That mileage is towing a 5600 lb Chevy Tahoe.

I guess some people can't handle the fact that the 6.7 ISB is a fuel efficient engine for a <30k lb rig.

[PushedAround]

We just drove from Philly to Cspe May, NJ. Gauging solely off of the computer we got 11 mpg driving the hills through South Eastern PA, and the when we got to the flatlands of NJ, we encountered a strong headwind which dropped our average down to 9.9. Based on that, you can see where a small difference in speed resulting in less headwind can produce a significant difference in mileage.

[CampDaven]

Originally Posted by Piker

We get a solid 10.5-11mpg... hand calculated over a 6200 mile trip out west and back. It was not downhill both ways. We ran our engine...

If you're getting less than 10 mpg, then your RV is probably heavier than 10 tons gvw and/or possibly burns gas instead of diesel.

-cheers

Interesting!

I would be interested in details of your rig. It is not in your profile.

I burn diesel and get 10.5 to 12.3 at 23,500 lbs, MH plus toad. I dont check long term mileage.