RV Trip Planning Discussions

Go Back   iRV2 Forums > THE OWNER'S CORNER FORUMS > Newmar Owner's Forum
Click Here to Login

Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on iRV2
 
Thread Tools Search this Thread Display Modes
 
Old 08-05-2018, 07:00 PM   #1
Senior Member
 
Join Date: Sep 2010
Posts: 3,048
DEF usage on K3 605 on 18 LA

Started checking DEF fluid usage on our 7K mile trip to Gillette and Newmar factory and surprised that we are only using 1 gallon of DEF every 175 miles. That seems low from what we have been reading on other coaches. Still getting excellent fuel economy above 7.5 miles per gallon.
Newmar Man
__________________

tom chelbana 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 08-05-2018, 07:30 PM   #2
Senior Member
 
Join Date: Mar 2014
Posts: 1,397
Tom it should be in the 3-5% of total fuel range. I get 220mpg for Dev on my ISL9.
__________________

__________________
Gary 2017 Dutch Star 4369 Spartan
HWH Active Air Centramatic wheel balancers
Box Elder, SD and the road
ghaynes754 is offline   Reply With Quote
Old 08-05-2018, 07:36 PM   #3
Senior Member
 
Mr_D's Avatar
 
Country Coach Owners Club
Winnebago Owners Club
Solo Rvers Club
iRV2 No Limits Club
Join Date: May 2011
Location: Vancouver, WA
Posts: 35,860
7.7 mpg is what I get with my ISX 650 and no DEF.
__________________
2009 45' Magna 630 w/Cummins ISX 650 HP/1950 Lbs Ft
Charter Good Sam Lifetime Member, FMCA, SKP
RV'ing since 1957, NRA Benefactor Life, towing '14 Jeep JKU
Mr_D is offline   Reply With Quote
Old 08-05-2018, 07:38 PM   #4
Senior Member
 
turbopilot's Avatar
 
Join Date: Aug 2017
Posts: 2,058
Quote:
Originally Posted by tom chelbana View Post
Started checking DEF fluid usage on our 7K mile trip to Gillette and Newmar factory and surprised that we are only using 1 gallon of DEF every 175 miles. That seems low from what we have been reading on other coaches. Still getting excellent fuel economy above 7.5 miles per gallon.
Newmar Man
If my math is right you are seeing DEF consumption around 4.3% of fuel flow which is high by historical standards but nominal for 2018 engines. What is surprising is 7.5 miles per gallon in that big coach. Over 8,000 miles that is the average mpg I am seeing in the little NA.
__________________
2018 New Aire 3343
turbopilot is offline   Reply With Quote
Old 08-05-2018, 09:05 PM   #5
Senior Member
 
Tranquil Jim's Avatar
 
Newmar Owners Club
Spartan Chassis
Join Date: Aug 2015
Location: Northwest Washington State or Western Montana, depending on the season.
Posts: 2,897
Quote:
Originally Posted by tom chelbana View Post
Started checking DEF fluid usage on our 7K mile trip to Gillette and Newmar factory and surprised that we are only using 1 gallon of DEF every 175 miles. That seems low from what we have been reading on other coaches. Still getting excellent fuel economy above 7.5 miles per gallon.
Newmar Man
I'd say that is excellent. Over the first 1K miles in our new MADP with 500 HP ISL 12, we are seeing about 185 mpg on DEF and 7.2 mpg on diesel. Hoping that as things loosen up, the fuel mpg will improve a bit.

We are impressed with the enhanced hill-climbing ability of the new coach over the 2014 VTLE with 340 HP ISB.

We'll be on the road again later this month through October, so will have a better opportunity to gauge both DEF and diesel mpg.

TJ
__________________
Jim (W7DHC), Diane & Mini Schnauzers, Lizzy & Ellie
2018 Mountain Aire 4047 + 2014 Honda CR-V "toad" w/AF1
Tranquil Jim is offline   Reply With Quote
Old 08-06-2018, 12:50 AM   #6
Senior Member
 
Stuart W's Avatar


 
Newmar Owners Club
Join Date: Nov 2015
Location: LA CA
Posts: 5,800
When checking your DEF usage, how are you tracking the amount of DEF used? are you letting the pump kick out, or more precisely, are you using a mark on the DEF tank and filling back up to that mark? The reason I ask is on my DS I find that you can put more then the 15 gallons the tank is said to hold. I have made a line that I try and use for accuracy. Thank you. Stuart w
__________________

2018 Dutch Star 4369 Spartan!
2017 Jeep Wrangler Smoky Mountain
2016 Canyon Star 3710 SOLD
Stuart W is offline   Reply With Quote
Old 08-06-2018, 05:22 AM   #7
Senior Member
 
NealC's Avatar


 
Newmar Owners Club
Appalachian Campers
Freightliner Owners Club
Join Date: Feb 2017
Location: Midlothian, VA
Posts: 4,326
Itís also important to note fuel MPG can vary drastically by several factors. To get an accurate value you should not fill at a truck stop at start and end of your measurement. If you slow fill (non truck stop) at the beginning and fast fill (truck stop) at the end you will have a lot of foam and skew your measurement. Slow fill and truly top off both sides then calculate. The larger the tank the more inaccurate the reading.

Average speed is the next major factor. You canít compare someone driving at 70 vs 55. The numbers will be hugely different.

DEF consumption probably needs to be measure on at least 50% consumption. Fill it up, log mileage, let it go down to 1 or 2 dots, fill it and measure.
__________________
Neal
2017 Newmar Ventana 4037, 1800W Solar, HWH Active Air
NealC is online now   Reply With Quote
Old 08-06-2018, 08:10 AM   #8
Senior Member
 
Stuart W's Avatar


 
Newmar Owners Club
Join Date: Nov 2015
Location: LA CA
Posts: 5,800
I also believe that driving conditions will change DEF usage. Example: you get on the highway reach cruising speed and regeneration starts, your plans are to pull off the highway for lunch prior to the regen finishing. Lunch is over and back on the highway only to find heavy traffic and you can only go 30 MPH for the next 45 minutes, finally you reach cruising speed and regen starts again, I have to feel this will use more DEF then just starting regen while cruising and continuing until regen is done. Thoughts?
__________________

2018 Dutch Star 4369 Spartan!
2017 Jeep Wrangler Smoky Mountain
2016 Canyon Star 3710 SOLD
Stuart W is offline   Reply With Quote
Old 08-06-2018, 08:44 AM   #9
Senior Member
 
NealC's Avatar


 
Newmar Owners Club
Appalachian Campers
Freightliner Owners Club
Join Date: Feb 2017
Location: Midlothian, VA
Posts: 4,326
I don't know...all I know is my DEF consumption is extremely low and I don't worry about keeping it topped off like I did when I started. After going to Camp Chassis (your flavor) class and learning you can go 1000mi when it hits empty, just don't turn the engine off, that took my worry away. So I drive until the DEF light hits 2 dots and then go for a period of time, i.e. end of trip DEF top off. Some like the stats, go for it, I just suggest with the Diesel be aware of the foaming, with DEF I suggest run the DEF as low as you comfortably can go as you need more gallons of burn to really get an accurate reading. We all know? MPG is low, low is low, we accept it, I drive fast as time is money, don't care about MPG, and DEF consumption is nothing to worry about nor is there anything you can really do to change it. Right now my worry is time between windshields :( Follow up on that in a few.
__________________
Neal
2017 Newmar Ventana 4037, 1800W Solar, HWH Active Air
NealC is online now   Reply With Quote
Old 08-06-2018, 08:51 AM   #10
Senior Member
 
turbopilot's Avatar
 
Join Date: Aug 2017
Posts: 2,058
Quote:
Originally Posted by NealC View Post
I don't know...all I know is my DEF consumption is extremely low and I don't worry about keeping it topped off like I did when I started. After going to Camp Chassis (your flavor) class and learning you can go 1000mi when it hits empty, just don't turn the engine off, that took my worry away. So I drive until the DEF light hits 2 dots and then go for a period of time, i.e. end of trip DEF top off. Some like the stats, go for it, I just suggest with the Diesel be aware of the foaming, with DEF I suggest run the DEF as low as you comfortably can go as you need more gallons of burn to really get an accurate reading. We all know? MPG is low, low is low, we accept it, I drive fast as time is money, don't care about MPG, and DEF consumption is nothing to worry about nor is there anything you can really do to change it. Right now my worry is time between windshields :( Follow up on that in a few.
Your point of view will change once you experience a major "DEF Crystalization Event". Chronically running DEF tanks lows promotes crystal growth all over the tank, level sensing equipment and other sensing components in the DEF storage system. I have been fighting the "DEF Wars" in diesel engines since 2011 when it all started. If you want to avoid spurious DEF alarms, warnings and shutdowns always run with the DEF tank as full as you can get it. There is a FreightLiner service letter on this subject talking about the impact of DEF crystalization "freezing" the DEF level float sensor.
__________________
2018 New Aire 3343
turbopilot is offline   Reply With Quote
Old 08-06-2018, 08:54 AM   #11
Senior Member
 
NealC's Avatar


 
Newmar Owners Club
Appalachian Campers
Freightliner Owners Club
Join Date: Feb 2017
Location: Midlothian, VA
Posts: 4,326
Thanks, I'll check into this. My understanding was DEF refill will dissolve any crystallization if that occurred, wasn't aware it would occur in this situation. In class there was discussion of DEF crystallization but more from old DEF vs. DEF level "not full" in the tank and new DEF would resolve it.
__________________
Neal
2017 Newmar Ventana 4037, 1800W Solar, HWH Active Air
NealC is online now   Reply With Quote
Old 08-06-2018, 09:45 AM   #12
Senior Member
 
turbopilot's Avatar
 
Join Date: Aug 2017
Posts: 2,058
Quote:
Originally Posted by NealC View Post
Thanks, I'll check into this. My understanding was DEF refill will dissolve any crystallization if that occurred, wasn't aware it would occur in this situation. In class there was discussion of DEF crystallization but more from old DEF vs. DEF level "not full" in the tank and new DEF would resolve it.
There is class and real life. DEF will dissolve "in time". But if you chronically run the DEF tank low large crystals can form towards the top of the tank that don't see any real "slosh" from below. If these crystals are obstructing a sensor it can take some time before the sensor is back on line after a refill.

There is another very important reason to run with a topped off DEF tank: marginally out of spec DEF. If you fill an empty tank with DEF slightly out of spec you will enjoy a shut down event. Filling a partially full tank with some out of spec DEF may avoid that event with dilution saving the day. Right now I am topping off my DEF every 4 or 5 gallons, either from the pump or from 2.5 gallon on board containers.
__________________
2018 New Aire 3343
turbopilot is offline   Reply With Quote
Old 08-06-2018, 11:23 AM   #13
Senior Member
 
Tranquil Jim's Avatar
 
Newmar Owners Club
Spartan Chassis
Join Date: Aug 2015
Location: Northwest Washington State or Western Montana, depending on the season.
Posts: 2,897
Interesting discussion regarding DEF. I was unaware of the crystallization issue. Guess it is good that I like to run on the top half of the fuel and DEF tanks.

TJ
__________________
Jim (W7DHC), Diane & Mini Schnauzers, Lizzy & Ellie
2018 Mountain Aire 4047 + 2014 Honda CR-V "toad" w/AF1
Tranquil Jim is offline   Reply With Quote
Old 08-06-2018, 11:26 AM   #14
Senior Member
 
NealC's Avatar


 
Newmar Owners Club
Appalachian Campers
Freightliner Owners Club
Join Date: Feb 2017
Location: Midlothian, VA
Posts: 4,326
I emailed FL (Mike Cody) to see what his guidance was and what he knew of the above stated info:

Quote:
Neal I can only find on the Freightliner system repair notes on inoperative DEF Tank levels to inspect float for crystalizing:

(When a vehicle equipped with a diesel exhaust fluid (DEF) system sits for an extended period of time, the DEF in the tank may crystallize around the float on the DEF level sending-unit tube and require cleaning. This crystallization may cause the float to stick on the tube)

I teach when storing (like I said in class) keep DEF tanks Full. When traveling fill DEF Tanks at 2 green bars or half . Setting 30 days, waiting to go on your next trip is not an issue. Tera industries and Valvoline both say if there are any crystals in the tank when you submerge them back in DEF the crystals dissolve.
__________________

__________________
Neal
2017 Newmar Ventana 4037, 1800W Solar, HWH Active Air
NealC is online now   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


Similar Threads
Thread Thread Starter Forum Replies Last Post
DEF Usage traveler of california iRV2.com General Discussion 14 10-11-2016 01:38 PM
DEF Usage dave&ginny Entegra Owner's Forum 30 12-03-2015 05:17 PM
DEF usage on the isx eng. loisjop Entegra Owner's Forum 19 07-14-2015 11:04 AM
What's your DEF usage in MPG? danleininger Newmar Owner's Forum 23 06-27-2014 10:08 AM
Trojan T-605 Question (T-105) CARVAL Motorsports MH-General Discussions & Problems 2 01-29-2009 05:38 PM

» Featured Campgrounds

Reviews provided by


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 10:27 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.