Regen Cycles 2023 RAM 3500 6.7 HO

[56ram2500]

You have a 2022, the OP has a 2023.

Well I guess I best go get my eyes checked as I missed it was a 2023

 

[Av8r7]

So does DEF get burned in the engine? And how would I use more DEF?

 

[mbarber84]

So does DEF get burned in the engine? And how would I use more DEF?

No, DEF is injected into the exhaust system after the DPF. It is sprayed into a chamber called the “SCR” (Selective Catalytic Reduction) where it mixes and reacts with the exhaust flow to remove Nitrogen Oxides (NOx) from the exhaust.

The amount of DEF sprayed into the exhaust depends on the amount of NOx being produced by the engine. The system has sensors that measure NOx values in the exhaust flow, and then the onboard processor adjusts the amount dosed into the SCR accordingly. In simplest terms, the more fuel the truck burns, the more DEF will be required to eliminate NOx.

NOx emissions are also reduced by a process called EGR (Exhaust Gas Recirculation) on the engine itself. Some of the engines exhaust flow is redirected back into the air intake and then run through the combustion cycle a second time. This is a less desirable way to reduce NOx emissions, due to the fact it introduces a lot of soot into the engines clean air intake. In 2013, Ram added the DEF / SCR on the truck in order to reduce the amount of EGR cycles the engine had to use to meet targeted NOx emissions level.

DEF greatly supplements EGR, and reduces the amount of EGR the truck uses to meet NOx emission values. More DEF = Less EGR

 

[AH64ID]

And less EGR is good for the engine.

I’d love to see a aftertreatment only setup.

 

[MEGA HO]

Did you get the truck with all the aftermarket add-ons installed or did you do it yourself? If later, how bad were the regens before that? Reason I'm asking you said you have Banks Intake Filter System (assuming the aftermarket air filter) and there seem to be a connection between using the correct air filter and regen frequency. Even some of the OEM air filters will make it regen excessively, there is a whole long winded tread on here about the filters and regen frequency.

Thanks for all the help.

As far as the 24 hour cycle I don't think that is even close. I drive 30 miles to work about 3-4 times a week. The idle down chart I have not found yet. I used to use 3 minutes, and later went to EGT when I had gages installed on my 5.9. Now the EGT will not come down in 3 minutes during a regen, but idling adds to the soot build up. Catch 22 here. Do you guys know if the dealer can adjust the regen cycle? Also the regen seems to take a very long time and fuel efficiency plummets.

All this emissions stuff just seems wrong and illogical to me. We are going to burn more fuel to reduce CO2? Meanwhile we trash the engines. There a some videos online showing the soot and carbon buildup in the intakes which in turn destroy efficiency. What I also find interesting is that Cummins Techs and MOPAR Techs will not give difinitive answers on what is best practice for avoiding trouble with this eco stuff.

Thanks again for the inputs.

You got it wrong. DPF, as the name suggest is a filter that catches soot, it has zero to do with CO2 or NOx emissions. All this modern emissions junk only reduces NOx at the expense of extra CO2 - more fuel burnt - more CO2 produced.

 

[AH64ID]

All this modern emissions junk only reduces NOx at the expense of extra CO2 - more fuel burnt - more CO2 produced.

That’s the beauty of DEF, it lets the engine run optimally and deals with NOx downstream.

I rather get 100mpg DEF and have no EGR, but the reduced EGR in the 19+ trucks is pretty nice.

 

[MEGA HO]

That’s the beauty of DEF, it lets the engine run optimally and deals with NOx downstream.

I rather get 100mpg DEF and have no EGR, but the reduced EGR in the 19+ trucks is pretty nice.

100% agreed!

 

[mbarber84]

That’s the beauty of DEF, it lets the engine run optimally and deals with NOx downstream.

I rather get 100mpg DEF and have no EGR, but the reduced EGR in the 19+ trucks is pretty nice.

Definitely.

1,410 miles on 2.5 gallons of Platinum DEF my last fill up.

That works out to just over 1¢ per mile. I’ll gladly pay $1,000 over 100,000 miles in order to reduce the amount of EGR the truck has to ingest.

 

[Av8r7]

Okay seems that we need an engineer to weigh in here. How can anything injected downstream of the engine's cylinder/combustion chamber increase fuel mileage? Let alone reduce EGR regen cycles.

On Friday night driving home from the hangar, I checked the DPF gauge, and it was still zero. 5 miles later it had jumped up to about 20%, but no regen cycle. Checked it another 5 miles later and it was back to zero. By the time I got home another 20 miles, I checked it again doing a 3 minute idle down, and it was back to 20%. Electronic sensors are in my experience not that reliable and thus the weak point in what "they" are trying to accomplish. When sensors fail or produce unreliable information in aircraft the system reverts back to a "manual" state for safety. Would appear to me that this wasn't done in the automobile world costing people lots of money in an effort force them to accept someone else's opnions.

I am all for clean air, but let's take a deep breath and do it right.

 

[AH64ID]

Okay seems that we need an engineer to weigh in here. How can anything injected downstream of the engine's cylinder/combustion chamber increase fuel mileage? Let alone reduce EGR regen cycles.

Fuel economy is improved because combustion efficiency is increased by reducing the EGR flow.

EGR reduces oxygen in the cylinder, which in turn lowers combustion temp and pressure. That’s what reduces NOx output. That also reduces efficiency. Less EGR = more efficient combustion.

By treating NOx downstream of the engine we let the engine run more efficiently.

There isn’t a function on these trucks called EGR regen.

On Friday night driving home from the hangar, I checked the DPF gauge, and it was still zero. 5 miles later it had jumped up to about 20%, but no regen cycle. Checked it another 5 miles later and it was back to zero. By the time I got home another 20 miles, I checked it again doing a 3 minute idle down, and it was back to 20%. Electronic sensors are in my experience not that reliable and thus the weak point in what "they" are trying to accomplish. When sensors fail or produce unreliable information in aircraft the system reverts back to a "manual" state for safety. Would appear to me that this wasn't done in the automobile world costing people lots of money in an effort force them to accept someone else's opnions.

I am all for clean air, but let's take a deep breath and do it right.

The truck won’t trigger an active regen until you’re around 45% in the EVIC screen. The truck is just reporting DPF loading based on what it senses. The up and down is based on DPF temps while you drive.

Nothing is what you described for your drive home indicates a 3 minute idle down time is required, you only need seconds after an empty drive home. Most of the cool down can occur coasting as much as possible the last 1/2 mile home. Your current turbo is also water cooled, so coking of the oil in the main turbo bearing isn’t an issue after empty driving.

 

[Av8r7]

Okay, now we are getting somewhere. Very good explanation of the system AH64ID! This is starting to make sense. One question remaining what creates more DEF usage?

 

[mbarber84]

Okay, now we are getting somewhere. Very good explanation of the system AH64ID! This is starting to make sense. One question remaining what creates more DEF usage?

More load on the engine and more fuel burned.
DEF consumption is directly proportional to fuel consumption. The more fuel you burn, the more DEF is required to offset the NOx produced by the combustion of that fuel.

 

[AH64ID]

Also, the harder you work the engine the lower the EGR flow rate is so that means that the DEF consumption per gallon of diesel increases.

I get ~700mpg DEF empty and ~350mpg towing. About 2.9% towing and 2.2% empty.

 

[Av8r7]

All good to know thanks