DEF usage on K3 605 on 18 LA

[NealC]

Originally Posted by Boomer;433575[emoji646

]I know this has been discussed elsewhere, but do you use the DEF at the pump or buy cartons?

I’ve heard bad stories about containers so I prefer at the pump.

[Dtwallace]

Originally Posted by Stuart W

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?

Sir in my experience, thats absolutely correct. DW and I just completed a trip from Fayetteville, NC to White Sulphur Springs, WV, and back where I was pushing old girl pretty hard both ways up and down the mountains.

This was a 500+ mile trip both ways and we used approximately 150 gallons of fuel. I didn't take exact measurements of fuel used but I did notice that we used almost none of the DEF I put in the tank before we left home.

I would estimate an hour and a half of idle time during the entire trip, and no regens at all.

To the contrary, in more in city, low speed light duty driving, I've experienced more regens and more DEF usage than we expected.

This is our first DEF vehicle, and at first when the high exhaust temp light would come on, we would stop to let it cool off like you mentioned in your scenario.

We've since discovered the best way to maintain the exhaust system in good working order, is to not baby it, but drive it hard within safety limitations of course, and within your comfort zone.

Don't park and fuel up during a regen because it gets very hot back there, and I've been concerned at times with the hot gases possibly lighting off spilled fuel on the ground.

I have set grass on fire during a regen and luckily wasn't a big area as it burned out before it was discovered.

I don't shut down until regen has finished if at possible.

[Ann n Gene]

Originally Posted by tom chelbana

To check our DEF usage on our 18 LA with Spartan K3 605 chassis we drove 1460 miles when we had filled DEF and then to refill DEF tank it needed 8.5 gallons. That worked out to 175 miles to use 1 gallon of DEF. For a 1% usage that would be 100 miles to 1 gallon of DEF. Going 175 miles to use 1 gallon DEF is almost .5% usage. Are we missing the usage of DEF?
Newmar Man

If you get 7 mpg and go 175 miles you use 25 gallons diesel, 1 gallon DEF equals 4% usage which is what my 2016 Cornerstone started out using. When it got over 20000 Miles it has slowed down to about 3%. DEF usage is usually reported as a percentage of diesel used. All JMHO

[Boomer]

Originally Posted by NealC

I’ve heard bad stories about containers so I prefer at the pump.

Thank you for your opinion,
Being relatively new to MH's in general (3 years now) and brand new soon to DP's I'm trying to get smart on all things DP. In gas'er land you just pump and go, no air bags, no DEF, some noise. Of course in DP land you have no noise, air bags (we test drove a Ventana LE) and more important to my way of thinking a real engine brake.

[Boomer]

Originally Posted by Dtwallace

Sir in my experience, thats absolutely correct. DW and I just completed a trip from Fayetteville, NC to White Sulphur Springs, WV, and back where I was pushing old girl pretty hard both ways up and down the mountains.

This was a 500+ mile trip both ways and we used approximately 150 gallons of fuel. I didn't take exact measurements of fuel used but I did notice that we used almost none of the DEF I put in the tank before we left home.

I would estimate an hour and a half of idle time during the entire trip, and no regens at all.

To the contrary, in more in city, low speed light duty driving, I've experienced more regens and more DEF usage than we expected.

This is our first DEF vehicle, and at first when the high exhaust temp light would come on, we would stop to let it cool off like you mentioned in your scenario.

We've since discovered the best way to maintain the exhaust system in good working order, is to not baby it, but drive it hard within safety limitations of course, and within your comfort zone.

Don't park and fuel up during a regen because it gets very hot back there, and I've been concerned at times with the hot gases possibly lighting off spilled fuel on the ground.

I have set grass on fire during a regen and luckily wasn't a big area as it burned out before it was discovered.

I don't shut down until regen has finished if at possible.

Excuse the naivety of the question, but how does one know it is doing a regen?

[Stuart W]

Originally Posted by Boomer

Excuse the naivety of the question, but how does one know it is doing a regen?

It is displayed on the dash while in regen

[Dtwallace]

Originally Posted by Stuart W

It is displayed on the dash while in regen

My indication is the high exhaust temp light.

As with any filter, they ‘filter’ or trap particles, in this case harmful diesel exhaust soot particles, so they have to be emptied regularly to maintain performance.

The DPF needs to be cleaned regularly, through a process called regeneration, either active, passive or forced regeneration, the accumulated soot is burnt off at high temperature (around 600°c) to leave only a residue of ash, effectively renewing or regenerating the filter, ready to take on more pollution from the engine.

The active system works off a filter load limit or sensors reading exhaust backpressure or the ‘soot load’ of the filter, activating timing adjustments to the fuel injection which in turn increases the exhaust temperature, initiating the burning of the soot and regenerating or clearing the filter.

Depending on the vehicle brand, This type of DPF regeneration can also be initiated by the vehicle ECU every 400 - 600 kilometres or so depending on vehicle use and takes around 10 minutes to complete. This is normal for light load driving/low speed city traffic (ect).



Some systems also use passive regeneration. For these vehicles passive regeneration generally takes place on the motorway where exhaust temperatures are higher.

This type of system can have an integrated oxidising catalytic converter located close to the engine where exhaust gases are hot enough so that passive regeneration is possible.

Passive regeneration, relies on the exhaust temperature being high enough to automatically burn off, (motorway driving) and or using the ECU to alter the vehicle timing to control the process.

In city driving or short trips the regeneration my not take place fully, or you may not allow it to complete, leading to blocking of the filter.

This can lead to higher fuel consumption and a visit to the mechanic for cleaning or replacement.


So in my first response, at high load mountain driving, I experienced passive regen and the light will never come on since the exhaust gasses are hot enough to keep the system clean without using much or any (DPF, hence my (DPF) level never changed throughout the trip.

Hope that clears some of the mud
DTW

[Boomer]

Originally Posted by Stuart W

It is displayed on the dash while in regen

Thank you

[10 fan]

With my first 4000 miles I have averaged 275 miles per 1 gal. of DEF. Sounds like I'm in the average.

[Stuart W]

Originally Posted by 10 fan

With my first 4000 miles I have averaged 275 miles per 1 gal. of DEF. Sounds like I'm in the average.

What is your MPG average?

[Breezy2006]

Originally Posted by Stuart W

It is displayed on the dash while in regen

Where is it displayed on the dash? We have a 17 Dutch Star Spartan and I do not recall seeing it ever with 18k miles. Thought I was attentive but perhaps not.

[ptw]

Don't know about the Spartan, but my Freightliner doesn't normally display anything about regen. Once I slowed down to exit the highway while it was in regen and I got an exhaust temperature warning light. If I hadn't slowed down there would not have been any indication that it was in regen. We discussed this incident in Camp Freightliner and I was told that is the way it is supposed to work for my engine.

[Stuart W]

Originally Posted by Breezy2006

Where is it displayed on the dash? We have a 17 Dutch Star Spartan and I do not recall seeing it ever with 18k miles. Thought I was attentive but perhaps not.

It is in the digital display area above the analog

[10 fan]

Originally Posted by Stuart W

What is your MPG average?

So far about 6.7mpg. Not sure how the 150 hours of generator time has affected the numbers. I will do better after I get more miles on it. I keep the rpm's up for break in purposes. A couple thousand more and I'll think about mileage.