|
|
06-26-2014, 11:06 AM
|
#15
|
Senior Member
Freightliner Owners Club
Join Date: Oct 2002
Location: Fairview TX
Posts: 2,458
|
Dan, that sounds reasonable to me also, but what about the other RVers getting lower consumption? Are they lead-footing it more than we are?
I agree with Jay....my coach seems to like 62-63mph better than 59-60 mph on my old ISM engine. So if your guy is right, the harder we push it the better our DEF mileage will be? But then there's the offset of higher diesel consumption. Guess we can't win.
Maybe we need to get the Gov't to mandate all, ALL electric MH's? NOT!!!!
__________________
Slabman
2019 Newmar Ventana 3717
2007 Lexus LX470 Toad
|
|
|
|
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!
|
06-26-2014, 12:49 PM
|
#16
|
Senior Member
Newmar Owners Club Spartan Chassis
Join Date: Feb 2012
Location: Lake Wales, FL (Lake Ashton RV Community)
Posts: 1,036
|
I'm not thinking we need any more government...nada, zip, zero,
__________________
Dan Leininger
2019 Mountain Aire 4534 and a 2017 Ford Expedition 4x4
|
|
|
06-26-2014, 01:25 PM
|
#17
|
Senior Member
Winnebago Owners Club
Join Date: Aug 2013
Posts: 1,636
|
So it sounds like everyone's all over the place on DEF consumption. Trying to figure out what the average DEF consumption should be. For me while not exact I figure I used about 5gl. DEF in 3000 miles, so what does this work out and where does it fit in the range what Cummins says the consumption should be. About 80% of my driving was at 60-65mph freeway driving.
__________________
2012 Journey 40U (Our Incredible Journey)
2008 Dodge Dakota(TOAD) 2005 Honda Shadow in TOAD
AF-1 braking system
|
|
|
06-27-2014, 12:43 AM
|
#18
|
Senior Member
Commercial Member
Join Date: Feb 2014
Location: Kent, WA
Posts: 127
|
Great thread topic!!!
D Lindy: 5 gallons of DEF in 3000 miles sounds about right to me for a high power diesel at the speed you stated. If your diesel mileage is around 10 MPG, that works out to 300 gallons of diesel for about 1.66% DEF/Diesel ratio which is good. My F350 6.7 is at about this ratio (closer to 2%) when fully loaded and driven at 65 MPH. The 6.7 has 400 HP and runs at around 15 lb. of boost for the conditions above.
Slabman: An electric MH?? Certainly possible (I've seen 500 HP electric vehicles but they ran the 1/4 mile) but range may be limited . More likely for a 2020 motorhome: A diesel electric setup that operates a clean diesel at optimal conditions for power and low emissions to charge batteries that operate electric motors. Kind of like today's trains. Check out a newer train at the train crossing next time. Those big appendages on the sides of the engine are DPF and SCR units. Newer units may use a more concentrated form of DEF (higher urea concentration).
capnqball: 300 MPG DEF works out to about 3.3% DEF/Diesel for 10 MPG diesel, 2.66% DEF/Diesel for 8 MPG diesel. Both of these values are still within what I would consider a normal range for DEF usage in a clean diesel. Provided there are no issues with the SCR system, DEF usage is a function of amount of NOx in the exhaust, urea to ammonia conversion efficiency (how well the DEF is atomized, mixed, and heated in the exhaust stream) and the SCR efficiency of the catalyst (how well the ammonia is used to convert NOx to N2, water, and CO2). NOx is created by high combustion pressure/temperature (primarily turbo boost and fuel/air ratios). Low power setting = less NOx = less DEF. High power setting = more NOx = more DEF. It's just that simple.
danleininger:
1. Every new diesel sold in North America after 2017 (RVs, trucks, trains, cars, light trucks, ships, recreational boats, buses, farm equipment, generators, mining, EVERYTHING) will be required to meet the 2010 EPA protocols for NOx which unless someone pulls a rabbit out of a hat, means SCR and thus DEF. This is the law enacted by the EPA. Some states are requiring retrofit of class 8 trucks made prior to 2010 on the same 2017 schedule. I don't have an opinion on whether Clean Diesels are good or bad government (although I generally agree with your opinion more government is not necessarily better for us but that's a subject for another thread ), but I can say this: My F350 truck gets great fuel economy for the job it does AND it is cleaner than almost any other vehicle on the road.
2. I'm surprised by your service manager's view on DEF consumption. Very surprised, since it is contrary to the thermochemistry of clean diesel engines, NOx, and SCR which I'm fairly well versed on. He is correct about increased particulate matter (PM) produced by running a diesel at lower than design power settings, AND heat IS required to (passively) burn off PM in your Diesel Particulate Filter (DPF) and an engine running at low power settings and rich fuel/air ratios will likely have more active regenerations. However DEF usage is essentially unrelated to DPF regeneration whether active or passive. It is true that a clean diesel engine can use more DEF at startup (before it warms up) since the after treatment system is well below it's design temperature for SCR conversion efficiency.
Another interesting point: Diesel fuel that can produce more NOx/HP (like B20) will likely cause the SCR system to use more DEF. I've observed this on my F350, and a farm operator I know that uses biofuels uses more DEF than when he runs plain diesel.
As always, please consider us an IRV2 resource for questions about DEF and Clean Diesels.
Erich
__________________
Erich Weinberg and Kathryn Whiting Five Star DEF
|
|
|
06-27-2014, 05:24 AM
|
#19
|
Member
Join Date: Jun 2014
Location: Wayland, MI
Posts: 84
|
This is one reason I LOVE our coach. NO DEF garbage that the Government mandates that the engine builders use. Good old Cummins 350HP with no "extras" on it to break, or cost extra money to run.
__________________
2002 Newmar Dutchstar 4097
2007 Jeep Grand Cherokee Diesel.
|
|
|
06-27-2014, 07:35 AM
|
#20
|
Member
Join Date: Apr 2012
Posts: 37
|
We have a 2014 MA with 450 Cummins. After 7200 miles we are averaging 5.2 MPG (includes Oasis and rare Gen usage). This equates to 19.3 gallons per 100 miles. Our DEF usage is 218.6 MPG and .46 gallons per 100 gallons. DEF adds about $ .03 per mile to our cost. DEF plus fuel cost us $ .76 per mile compared to our Dynasty with 500 Cummins at $ .78 per mile. I used this year's average cost per gal of diesel ($3.78) for the comparison so last year's higher prices didn't skew the cost per mile. We average 60 - 65 miles per hour and have been traveling in fairly flat country so no real loads on either engine. The 450 with DEF saves us $ .02 per mile ($144 so far this year) over the 500 without DEF.
__________________
Debbie, David, and Sparkle the Westie
2014 Molten Metal MADP 4361, Cummins 450
2014 Silver RAM 1500
|
|
|
06-27-2014, 07:41 AM
|
#21
|
Senior Member
Newmar Owners Club Spartan Chassis
Join Date: Feb 2012
Location: Lake Wales, FL (Lake Ashton RV Community)
Posts: 1,036
|
Quote:
Originally Posted by FiveStarDEF
danleininger:
1. Every new diesel sold in North America after 2017 (RVs, trucks, trains, cars, light trucks, ships, recreational boats, buses, farm equipment, generators, mining, EVERYTHING) will be required to meet the 2010 EPA protocols for NOx which unless someone pulls a rabbit out of a hat, means SCR and thus DEF. This is the law enacted by the EPA. Some states are requiring retrofit of class 8 trucks made prior to 2010 on the same 2017 schedule. I don't have an opinion on whether Clean Diesels are good or bad government (although I generally agree with your opinion more government is not necessarily better for us but that's a subject for another thread ), but I can say this: My F350 truck gets great fuel economy for the job it does AND it is cleaner than almost any other vehicle on the road.
2. I'm surprised by your service manager's view on DEF consumption. Very surprised, since it is contrary to the thermochemistry of clean diesel engines, NOx, and SCR which I'm fairly well versed on. He is correct about increased particulate matter (PM) produced by running a diesel at lower than design power settings, AND heat IS required to (passively) burn off PM in your Diesel Particulate Filter (DPF) and an engine running at low power settings and rich fuel/air ratios will likely have more active regenerations. However DEF usage is essentially unrelated to DPF regeneration whether active or passive. It is true that a clean diesel engine can use more DEF at startup (before it warms up) since the after treatment system is well below it's design temperature for SCR conversion efficiency.
Another interesting point: Diesel fuel that can produce more NOx/HP (like B20) will likely cause the SCR system to use more DEF. I've observed this on my F350, and a farm operator I know that uses biofuels uses more DEF than when he runs plain diesel.
As always, please consider us an IRV2 resource for questions about DEF and Clean Diesels.
Erich
|
Don't get me wrong on this one. I'm thrilled with the new clean diesel technology. And, I will proclaim that EPA got this ONE right! The fact that the back of my coach and the mud flap are not covered with diesel soot clearly demonstrates how effective this system is. Additionally, being told that this diesel can be run in an enclosed workshop without ventilation blows me away. I'm all for cleaner air! Who isn't??? Unfortunately on a world scale, until China and India get their act together all that we are doing here in the US will have little impact, globally speaking. End of my soapbox.
It does seem that the ISX engines in the King Aire and Essex do consume more DEF than the other engines. Why??? I don't have a clue.
Erich, as always, thanks for your input and knowledge.
__________________
Dan Leininger
2019 Mountain Aire 4534 and a 2017 Ford Expedition 4x4
|
|
|
06-27-2014, 08:57 AM
|
#22
|
Senior Member
Join Date: Aug 2010
Location: MI & AZ
Posts: 242
|
I have put about 5200 miles on my 400HP ISL since purchase. I have added 10 boxes of DEF and 732 gallons of fuel. Both tanks full with these numbers now. That works oiut to about 30:1 diesel to DEF or about 3.33%
__________________
Ted & Ruth Ann Hindes - NKK AZ State Directors
2014 Newmar Ventana 4377, 1400 Watts of Solar, Air Force 1 Brake, 2014 Grand Cherokee Overland
|
|
|
06-27-2014, 09:24 AM
|
#23
|
Senior Member
Freightliner Owners Club
Join Date: Oct 2002
Location: Fairview TX
Posts: 2,458
|
Dan, I'm with you all the way! Remember, the Euros have used this technology for years, so we didn't have to go through much of a learning curve. Before I bought, I checked with my coach building friend in Australia and he told me it iS a proven technology and I'd be happy with it.
The thought that use of B20 would increase DEF consumption bothers me a little. This is typical Gov't gobbleygook...the mandationg of a particular thing/product, THEN along come further mandates of what to do to mitigate that requirement. When does it all end?
And Dan's right. While we reap some direct benefits by using DEF, when others around the world are spewing new contaminants into the air on a daily basis, who are we fooling? Ouch! Hurt my old hip joint when jumping off MY taller soapbox.
__________________
Slabman
2019 Newmar Ventana 3717
2007 Lexus LX470 Toad
|
|
|
06-27-2014, 10:08 AM
|
#24
|
Senior Member
Join Date: Nov 2009
Location: Bainbridge Island, Wa
Posts: 557
|
Im sure glad I have an old ISB Cummins.
__________________
2004 Newmar Kountry Star Diesel Pusher, Chevy Tracker, Kizzy, Desi,Rosie, Red Ryder and Trek our Vizsla's
|
|
|
|
|
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
|
|
Thread Tools |
Search this Thread |
|
|
Display Modes |
Linear Mode
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
|
» Recent Discussions |
|
|
|
|
|
|
|
|
|
|
|
|
|