Community Forums

3rd stage · 09-27-2013, 08:39 PM

'95 37ft Beaver Pat. Mechanical 8.3 Cummins- Seattle to Southern Oregon 9.3mpg. Round trip over Stevens Pass to E. Washington 8.7mpg. Calculated based on gallons put back into the tank divided by actual miles travelled.

Happy with that!!

Bompa13 · 09-29-2013, 05:47 PM

Just purchased a 2008 Fleetwood Excursion with 360HP ISC Cummins with 6 speed Allison. I am towing my 2012 Silverado 4X4 for work. On a trip across PA to Philly area then up to upper NY for a job then over by NYC then home to NW PA we averaged in the upper 7's for MPG. with the terrain and perhaps my inexperience I am happy with this. Can always hope for better but believe fuel quality seems to change in different areas.

Herman Snerd · 09-30-2013, 07:00 PM

We did 3501 miles this past summer: Texas to California and back. Average for the trip was right at 8mpg - 7.9MPG to be exact. 2010 Fleetwood "Discovery" 40G with 350HP Cummins.

joeplazek · 10-17-2013, 09:13 PM

1996 Monaco Signature 450hp Cummins Allison Auto,,- Towing 7mpg not towing 8mpg and that's it folks!!

greg-1 · 10-18-2013, 09:47 AM

You all are getting some great mileage or my math and pocket book it wrong about 6.0-6.5 is what i am getting 500 Cummins 45 ft coach which may be the diff some didnt say size of coach and engine

Steve Ownby · 10-18-2013, 10:08 AM

Quote:

Originally Posted by greg-1

You all are getting some great mileage or my math and pocket book it wrong about 6.0-6.5 is what i am getting 500 Cummins 45 ft coach which may be the diff some didnt say size of coach and engine

The Cummins ISM is capable of very good economy. How fast do you drive and what is your average travel weight including tow? As a reference, I have the ISM also and drive 60-62 on Interstates. My travel weight is about 44-45k. My last 1,000 mile trip averaged 8.5 which was the best in some time. My lifetime average over 98k is 7.8.

You have an EGR valve which has caused some issues in the ISM and is known to have taken a bite out of the Milage.

Maladjusted · 10-18-2013, 10:11 AM

Seems like the the 50 hp increases in power decrease mpg by 1.

My 6.7 ISB at 28k lbs pulling a 3k toad gets 10 mpg hand calculated over a 1400 mile run up to New England and back to Va.

Seems like the 350 hp motors are getting 8-9 mpg, the 400 hp powerplants are 7-8 and the 450 to 500 hp jobbers are 6-7.

I would love to have a 500 hp smoker... But right now I am perfectly satisfied with burning 100 gals to travel 1000 miles!

Mal

calhyatt · 10-18-2013, 10:21 AM

Quote:

Originally Posted by Maladjusted

Seems like the the 50 hp increases in power decrease mpg by 1.

My 6.7 ISB at 28k lbs pulling a 3k toad gets 10 mpg hand calculated over a 1400 mile run up to New England and back to Va.

Seems like the 350 hp motors are getting 8-9 mpg, the 400 hp powerplants are 7-8 and the 450 to 500 hp jobbers are 6-7.

I would love to have a 500 hp smoker... But right now I am perfectly satisfied with burning 100 gals to travel 1000 miles!

Mal

I agree. My little 330 Cat gets us down the road. 8.6-9.6 depending on conditions. I would like you like a big motor but for now I am happy with my Cat.

greg-1 · 10-18-2013, 10:35 AM

Quote:

Originally Posted by Steve Ownby

The Cummins ISM is capable of very good economy. How fast do you drive and what is your average travel weight including tow? As a reference, I have the ISM also and drive 60-62 on Interstates. My travel weight is about 44-45k. My last 1,000 mile trip averaged 8.5 which was the best in some time. My lifetime average over 98k is 7.8.

You have an EGR valve which has caused some issues in the ISM and is known to have taken a bite out of the Milage.

40-45 on weight don't really matter much on toad which I thought was strange since my toad is 6200 lbs

greg-1 · 10-18-2013, 10:36 AM

Forgot speed 60-65

Jfhaas · 10-19-2013, 08:09 PM

There is an old saying. "Figures don't lie, but liars figure". I'm not calling anyone a liar but some of the figures seem seem out of whack. Seem like we are trying to justify the money we are all spending. Ever get into a milage conversation at a campsite with your fellow travelers. Seems like we all exaggerate a little. Just some thoughts. Jack

TerryO · 10-19-2013, 08:21 PM

Entegra Aspire 42'RBQ towing a Ford Edge, ISL450, running consistent 65, last trip Texas Indiana round trip 8.2 mpg. DEF runs somewhere around 1 gallon for every 50 gallons of fuel.

Maladjusted · 10-19-2013, 08:24 PM

Not really sure how more to "justify". Frankly I don't really care about mileage. I am not driving it every day... Or every week for that matter.

It just is what it is. From my log book: 10/9 746 miles. Towing - Tahoe. 75 gal.

I am a pilot, so I know the importance of logbook accuracy.

Alan JS · 10-20-2013, 07:21 AM

[QUOTE="TerryO;1773141"]Entegra Aspire 42'RBQ towing a Ford Edge, ISL450, running consistent 65, last trip Texas Indiana round trip 8.2 mpg. DEF runs somewhere around 1 gallon for every 50 gallons of fuel./QUOT

Also having a ISL 450 Entegra DLQ I accept the mileage I get with a speed of 63-65mph. However that additional expense of adding DEF really annoys the crap out of me. That fluid is not cheap and burns through quickly. Wish they had left the exhaust alone as the DEF does not improve power or mpg at all. There are few diesel motorhomes on the road so we cannot be blamed for causing an end to the world. DEF is another responsibility while traveling. At least it is very accessible through the bay doors.