Free 7 Day Trial RV GPS App RV Trip Planner RV LIFE Campground Reviews RV Maintenance Free 7 Day Trial ×
RV Trip Planning Discussions

Go Back   iRV2 Forums > POWER TRAIN GARAGE FORUMS > Cummins Engines
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
Reply
 
Thread Tools Search this Thread Display Modes
 
Old 06-08-2013, 12:21 PM   #1
gMw
Senior Member
 
gMw's Avatar


 
Fleetwood Owners Club
Freightliner Owners Club
Carolina Campers
Join Date: Dec 2002
Location: Conway, SC, USA
Posts: 822
DEF Consumption Rate

Our 2013 Fleetwood Expedition has a Cummings ISB10, 6.7 L, and uses DEF.

I’ve seen a lot of posts about MPG. I’m wondering if anyone is tracking the DEF Consumption Rate? If so, I'd like to get your feedback on the DEF Consumption Rate your engine is getting.

Based on the reading I’ve done, my expectation was the ISB10 would consume 1 gallon of DEF for every 50 Gallons of Diesel fuel. Or a 2% consumption ratio (DEF to Diesel).

Based on actual DEF/Diesel consumption, the ratio is over 3%, so it’s using 50% more DEF than expected.

BTW: The MPG with the ISB10 started out in the upper 8’s (almost 9), but quickly dropped to about 8.1… I know a lot of factors go into figuring MPG, BUT the net result is a drop in the MPG (the 2002 CAT 3126 we traded in got 8.25 to 8.5 mpg, same length, almost the same weight, and towing the same weight).
__________________
George & Laraine
and The Golden Ones, Montana & Sierra
2013 Expedition 38s, 2014 Jeep Wrangler Unlimited
gMw is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free!

iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 06-08-2013, 12:33 PM   #2
Senior Member
 
Maladjusted's Avatar
 
Join Date: May 2013
Posts: 300
My DEF consumtion is about what Cummins literature states.

I used 4 gallons in 2k miles.. .500 miles per gallon. I get 10.5 Mpg, so I am about right on.

Mal
__________________
-------------------------
2013 Coachmen SportsCoach 385DS
2010 HD CVO StreetGlide
Maladjusted is offline   Reply With Quote
Old 06-08-2013, 02:23 PM   #3
Senior Member
 
traveler of california's Avatar
 
Freightliner Owners Club
Join Date: Jul 2001
Posts: 1,481
I have an older coach, therefore no DEF. I'm curious as to where you purchase the stuff and what is the cost per gallon?

Nick
traveler of california is offline   Reply With Quote
Old 06-08-2013, 02:28 PM   #4
Senior Member
 
Foretravel Owners Club
Join Date: Apr 2010
Posts: 511
My Cummins (2) do ot use DEF, however we do have 2 Ford 6.7 Power Stroke F350 service trucks using the DEF, they run about 800 Mlles per gal.

No idea, but guessing a different program or what ever. May be due to lighter loading, they run about 9,000 lb normal weight
.
Just guessing.
Dave M
__________________
Foretravel, 2001, 36' ISM500 "Hot Rod"
F150 w/EZ Golf Cart or
CanAM 800 Max Limited ATV
Genset is offline   Reply With Quote
Old 06-08-2013, 04:00 PM   #5
Moderator Emeritus
 
JMonroe's Avatar


 
Newmar Owners Club
Winnebago Owners Club
Freightliner Owners Club
RV Trip Wizard
Join Date: Oct 2009
Location: Poinciana FL
Posts: 7,720
Cummins estimated about a 2% DEF to fuel ratio and our "real world" experience shows that to be just a hair high, we use a touch less. (A gallon of DEF for every 50 gallons of diesel - using Cummin's estimate). Ours does come out very close to Malajusted's one gallon for every 500 miles, which would suggest I'm getting 10 miles per gallon, using Cummins estimate, but I'm not. My trip planning is done assuming 7 miles per gallon - thus I'm beating the 2% estimate (I'm using less DEF than the estimate).

Our engines, however, may not be representative of what you'll get with yours.
__________________
Jay & Peggy Monroe with Dolly
Can't take it with you - don't plan on leaving any behind
2016 Newmar London Aire 4553, Spartan chassis
2020 Jeep Wrangler toad
JMonroe is offline   Reply With Quote
Old 06-08-2013, 04:20 PM   #6
Senior Member
 
gmadams's Avatar
 
Thor Owners Club
Freightliner Owners Club
Join Date: Aug 2011
Location: Jamestown, NC
Posts: 1,579
Quote:
Originally Posted by traveler of california View Post
I have an older coach, therefore no DEF. I'm curious as to where you purchase the stuff and what is the cost per gallon?

Nick
Some truck stops sell DEF at the pump. I just purchased some at the pump at a TA truck stop. It was $2.89 a gallon. Otherwise you have to purchase it in 1 or 2.5 gal containers and the cost is significantly higher.
__________________
Gary and Kay & Chipper
2018 Thor Tuscany 38SQ
2019 Ford Ranger XLT Super Crew
gmadams is offline   Reply With Quote
Old 06-08-2013, 05:04 PM   #7
Registered User
 
Join Date: Feb 2008
Posts: 3,607
We ave a Cummins 450 ISL and my DEF use is running from 4929 to 5570 miles on 15 gal. That's 328 to 321 miles per gallon over the 15,000 miles we have on the rig. We're in Alaska now and I have to fill the DEF before we start home in Sept. Couldn't find any places that sold bulk DEF up here, So I brought mine from home in 3 5gal cans. We filled up in Ohio and Shelby, MT just before getting to Canada. PITA and we're definitely not seeing any super fuel mileage on the rig while using it. We get about 6.75 so far on a 41,000 lb rig with a 6000 lb toad.
Pigman1 is offline   Reply With Quote
Old 06-08-2013, 06:53 PM   #8
gMw
Senior Member
 
gMw's Avatar


 
Fleetwood Owners Club
Freightliner Owners Club
Carolina Campers
Join Date: Dec 2002
Location: Conway, SC, USA
Posts: 822
Thanks for the replies...

Over 2,000 miles, our motorhome consumes 7.5 to 8 gallon of DEF, based on fuel used, I would have expected it to consume 5 gallons.

Due to the fact that our DEF Tank fill is on the right side, and all the truck stops I've been to have the DEF pumps on the left, we have only been able to buy DEF in bulk once, at a cost of $2.80 per gallon.

At truck stop 'stores', I've purchased DEF in 2.5 gallon containers at a cost of $15. Recently, I've found DEF in 2.5 gallon containers at Walmart for $11.97.
__________________
George & Laraine
and The Golden Ones, Montana & Sierra
2013 Expedition 38s, 2014 Jeep Wrangler Unlimited
gMw is offline   Reply With Quote
Old 06-08-2013, 07:07 PM   #9
Moderator Emeritus
 
JMonroe's Avatar


 
Newmar Owners Club
Winnebago Owners Club
Freightliner Owners Club
RV Trip Wizard
Join Date: Oct 2009
Location: Poinciana FL
Posts: 7,720
gMw, that does sound very high. I'd expect roughly 3500 miles on 8 gallons of DEF. Unless you're getting only 5mpg, which I'd think was a different problem, I think I'd talk to your chassis manufacturer about excessive DEF use.
__________________
Jay & Peggy Monroe with Dolly
Can't take it with you - don't plan on leaving any behind
2016 Newmar London Aire 4553, Spartan chassis
2020 Jeep Wrangler toad
JMonroe is offline   Reply With Quote
Old 06-08-2013, 07:25 PM   #10
gMw
Senior Member
 
gMw's Avatar


 
Fleetwood Owners Club
Freightliner Owners Club
Carolina Campers
Join Date: Dec 2002
Location: Conway, SC, USA
Posts: 822
Jay,

I'm taking our Expedition to Decatur the end of July. I'll have the chassis tech at Fleetwood Service look at the fuel mileage and DEF consumption issue than.
__________________
George & Laraine
and The Golden Ones, Montana & Sierra
2013 Expedition 38s, 2014 Jeep Wrangler Unlimited
gMw is offline   Reply With Quote
Old 06-09-2013, 02:21 AM   #11
Senior Member
 
photoguy1313's Avatar
 
Join Date: Dec 2010
Location: Charlotte, NC
Posts: 158
Quote:
Originally Posted by gMw View Post
At truck stop 'stores', I've purchased DEF in 2.5 gallon containers at a cost of $15. Recently, I've found DEF in 2.5 gallon containers at Walmart for $11.97.
I encountered the same problem yesterday at a Love's truck stop - couldn't fill me DEF tank because of where the DEF dispenser was located.
I had purchased a 2.5 gallon container at Walmart, filled my tank at the time and saved the container with its dispensing hose. I refilled the container at $2.699 per gallon and will fill my DEF tank from that. This might become my standard workaround ...

Norb
__________________
Norb and Ellen & Carly
2018 Tiffin Allegro RED 37PA

2005 Honda Pilot toad
photoguy1313 is offline   Reply With Quote
Old 06-09-2013, 04:20 AM   #12
Senior Member
 
JohnBoyToo's Avatar
 
Monaco Owners Club
Join Date: May 2012
Location: DFW, Tex-US
Posts: 6,196
Be careful reusing bottles....

the def will crystalize if left to it's own devices

our ford trucks have a def heater to keep it liquid... would assume the pushers do too, but out in the air - once it sets up it will turn to crystals....

(and for a different perspective, I use the Pilot / Flying J phone app to find their def pumps - last I did it was 2.79/gal...)
__________________
'11 Monaco Diplomat 43DFT RR10R pushed by a '14 Jeep Wrangler JKU. History.. 5'ers: 13 Redwood 38gk(junk!), 11 MVP Destiny, Open Range TT, Winn LeSharo, C's, popups, vans, tents...
JohnBoyToo is offline   Reply With Quote
Old 06-09-2013, 08:15 AM   #13
Moderator Emeritus
 
JMonroe's Avatar


 
Newmar Owners Club
Winnebago Owners Club
Freightliner Owners Club
RV Trip Wizard
Join Date: Oct 2009
Location: Poinciana FL
Posts: 7,720
gMw, you'll love camp Decatur.

Gravel parking lot with 50 amp hookups. We've spent our share of nights there. Of course the 5AM wakeup is fun too, so they can come get your coach by 6. At least the trains (running right next to the "campground") aren't too frequent.
Attached Thumbnails
Click image for larger version

Name:	Camp Decatur 10-23-2011.jpg
Views:	104
Size:	327.1 KB
ID:	40404  
__________________
Jay & Peggy Monroe with Dolly
Can't take it with you - don't plan on leaving any behind
2016 Newmar London Aire 4553, Spartan chassis
2020 Jeep Wrangler toad
JMonroe is offline   Reply With Quote
Old 06-09-2013, 09:43 AM   #14
Senior Member
 
photoguy1313's Avatar
 
Join Date: Dec 2010
Location: Charlotte, NC
Posts: 158
Quote:
Originally Posted by JohnBoyToo View Post
Be careful reusing bottles....

the def will crystalize if left to it's own devices

our ford trucks have a def heater to keep it liquid... would assume the pushers do too, but out in the air - once it sets up it will turn to crystals....

(and for a different perspective, I use the Pilot / Flying J phone app to find their def pumps - last I did it was 2.79/gal...)
Not sure what you're saying about crystallizing - do you mean in freezing temps? Or crystallizing when exposed to air? I wasn't suggesting long-term storage in the reused container, merely collecting at a fuel stop with later filling into the coach tank.

Norb
__________________
Norb and Ellen & Carly
2018 Tiffin Allegro RED 37PA

2005 Honda Pilot toad
photoguy1313 is offline   Reply With Quote
Reply



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


» Featured Campgrounds

Reviews provided by


All times are GMT -6. The time now is 09:29 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2022, vBulletin Solutions, Inc.