Reducing Emissions in a Modern Diesel Engine

[Heli_av8tor]

As a newcomer to diesel power I found this interesting and informative. You may too.

 

[Larry N.]

Nice, Tom-- thanks.

 

[bigbAZ]

I've subscribed to this blog for years, very good info for those interested. Below is just one of their recent articles, on their home page there are many more.

Industry Ready to Deliver Cleanest Diesel Engines Yet for EPA 2027

Over the last month, one message has come through loud and clear: truck and engine manufacturers are ready for the latest U.S. Environmental Protection Agency (EPA) engine emission standards. The new standards, which take effect in 2027, are not a minor tweak. They sharply reduce allowable...

enginetechforum.org

 

[TheBar]

EPA Removes DEF Sensor Requirements Saving Americans Billions Annually

Trump EPA to delay Tier 4 air pollution standards

 

[Brad Buchanan]

As a newcomer to diesel power I found this interesting and informative. You may too.

Makes me want to keep our 2004.

 

[Derby6]

Yea thats a mouthful.
Got me to thinking---- I think I can have my pickups reprogrammed to not go into limp mode if there is a DEF sensor issue. Need to talk to the dealer this week and find out.
1. Can they do this on my 2019 and 2022?
2. Is there a cost and is so how much?

 

[bigbAZ]

Yea thats a mouthful.
Got me to thinking---- I think I can have my pickups reprogrammed to not go into limp mode if there is a DEF sensor issue. Need to talk to the dealer this week and find out.
1. Can they do this on my 2019 and 2022?
2. Is there a cost and is so how much?

I wish I knew but please post back what they say. The way I understand it is the de-rates will be relaxed a bit on new vehicles but not eliminated. I haven't seen anything on existing vehicles.

Engine Technology Forum Webinar Clarifies Role of SCR and DEF Amid Recent EPA Guidance

WASHINGTON (April 21, 2026) – The Engine Technology Forum (ETF) today announced the availability of the recorded version of its April 20 webinar, “Making Diesel Clean: What You Need to Know About SCR and DEF,” which brought together technical experts and industry leaders to explain the role of...

enginetechforum.org

SCR and DEF in Context: What Policymakers Should Know About Diesel Emissions, Reliability, and Recent EPA Guidance

Recent headlines and policy discussions have placed Selective Catalytic Reduction (SCR) and diesel exhaust fluid (DEF) squarely in the spotlight. Questions about system reliability, regulatory flexibility, and the future of diesel emissions control have created both confusion and opportunity. An...

enginetechforum.org

 

[Derby6]

I think:
Currently it’s an almost immediate 5mph derate. BIG TIME issue when trucks on a highway and/or climbing with a load. Not to mention stops farm work immediately.

New rules about 400 miles then minimal derate that allows flow with traffic.
Then at about 2500 miles 25mph derate.
Gives you time to get to and repair issue.

 

[ddm502001]

Is in the works by Mr Zeldin to dramatically remove all this encumbering nonsense. Original 'Determinations' from CARB in California stated Reducing Sulphur in Diesel Fuel would reduce particulates by at least 50%, problem was they failed to consider that reduction of a BTU value in the Fuel increased consumption rates. The emission reduction was compensated for by the added fuel to make HP. So the genius that is NON Science/Agenda based CARB became ever more determined to prove were correct and came out that Elimination of Sulphur(Costly process) would eliminate all particulates, HOWEVER that was a lie as Diesel cannot be reduced to Zero Sulphur economically, reducing to current values is and not ever been Economical. Thus the delivered Particulate levels stayed pretty well Flat.
Move to Mode Two; add EGR to Combat Oxides of Nitrogen created in higher volumes as more fuel was consumed and in as much as 14:1 Combustion values, more air at 78% Nitrogen involved, thus had a Secondary Increased emission. Followed by a Loss of HP that required MORE Fuel so instead of removing Junk the manufacturers increased Combustion Compression pressures to 18:1 from 15 or 16:1, Added More Turbocharger Boost and attempted to create better HP on low viability Fuel Supplies. Now Mind you the EPA is supposed to have the Finest Scientific Minds and they set these events into these cascading events. Thus the Required Addition of DOC(Diesel Oxidation Catalyst) Systems to consume the NOX, and convert to some other form of release while trapping carbon residue of Unburned fuel.
Mode Three tests:
NON Typical operational testing done to prove validity by running the engines as seated on Dynamometers at 80% Rated Power continuous load. Typically Diesels in Automotive environs may attain 75-90% max HP delivered for 20-25% of their running lifetimes. On Highway with a Rated Licensed Load they can attain on average 28-30% full Load power at any given point of travel. DOC systems required 1200 degrees F to trigger Catalyst action so to manage that a Added Fuel injector device was placed at exhaust of Turbocharger or inlet of DOC Catalyst bed to increase heat load artificially. Anyone see the Self Eating Feeding Watermelon yet?

End result was Fuel Consumptions Increases with as little as 16-18% typical REDUCTION of Released Emissions where the Dyno Tests attained a Max Reduction of 25% released materials yet did not note the Increased Fuel Consumption per mile to achieve that. Basically, Emissions remained as a Constant in a Per Mile to gal Fuel Consumed ratio. They achieved nothing but costing to an extreme and consuming More Fuel. That is why all this Not Science malarky is being slowly cancelled in EPA Coding that was pushed by an agenda in CA to remove IC Engines especially Diesels. Unelected Agencies were allowed by Congress to apply Codes Rules not legislated Laws as a Law to be enforced, where to remove said Codes takes an action of Congress or an address by the agency to have the Code Removed. As to the DPFs inserted in these DOC canisters, typical cleaning processes are to remove Filter and Flush out in a Pressure Washer Bay at a garage or vacuum out placing into packaging to be hauled to landfills or as most mechanics do, take outside and BLOWGUN deposits into the air. Removed Nothing from Environment.

 

[UTTransplant]

Having lived in a high air pollution area (Salt Lake City environs) and having done a lot of work in other high air pollution areas (LA basin, Denver), the cleanup of the air is almost unbelievable. Even with the LA basin area having almost twice as many people as it did 35 years ago when I started doing a lot of work there, the air is astonishingly cleaner. I used to joke that LA didn’t really have mountains to the east since they were never visible; not anymore! You can scoff all you like about the regulations, but the results can not be disputed. The air is so, so, so much cleaner than it was 30-40 years ago. And it isn’t just a visual thing. Bad air is correlated with higher rates of premature births (which correlates with serious complications for the babies), higher rates of lung diseases including asthma and COPD, and higher rates of heart disease. I will gladly take the complications of emissions controls in order for those complications to be minimized.

 

[bigbAZ]

I used to joke that LA didn’t really have mountains to the east since they were never visible

I'm reminded of Shelly West's lyrics in my favorite Country duet, which came out 46 years ago:

Sometimes when the wind blows you can
See the mountains
And all the way to Malibu

 

[ddm502001]

Most Emissions do not come from Auto and defined NOT truck Diesels, most came from old manufacturing processes no longer used. A great many manufacturing Plants have completely Closed and Moved OVERSEAS.

 

[Tom]

I used to joke that LA didn’t really have mountains to the east since they were never visible;

Back in the olde country (a long time ago), one of our technology 101 teachers introduced us to smog. He had previously worked 10 years for a pollution monitoring office in LA (EPA?); He showed us time-lapsed photography, taken over 24 hours, looking into the LA basin from the surrounding mountains. It showed what looked to us like huge clouds rolling in, smothering the basin, and rolling out again.

I didn't really appreciate the smog issue until we moved to the Bay Area some years later.

Our local joke in the (very wet) olde country was that, if you stood on the beach and could see a well-know community across the bay, it was going to rain; If you couldn't see it, then it was already raining.

 

[Kirk]

Our local joke in the olde country was that,

Back in the 1960's there was a saying that on a clear day in CA you can see downtown LA from downtown LA.

 

[Gr8bawana]

Yea thats a mouthful.
Got me to thinking---- I think I can have my pickups reprogrammed to not go into limp mode if there is a DEF sensor issue. Need to talk to the dealer this week and find out.
1. Can they do this on my 2019 and 2022?
2. Is there a cost and is so how much?

I can assure you a dealer will do no such thing.

 

[Gr8bawana]

Yes by all means let's go back to the good old days before pollution controls.

 

[Derby6]

Let’s be real. Less pollution haze in many cities has reduced in past 60 years because of plants of everything from power plants to manufacturing plants have cleaned up.
This improvement is not because our diesel motor exhaust reform/improvements.

 

[ddm502001]

I can assure you a dealer will do no such thing.

Will have to go to an Engine Specific Shop.

 

[TheBar]

California wildfires every year emit as much carbon as almost 2 million cars, posing a threat to efforts to battle climate change.

 

[Derby6]

I can assure you a dealer will do no such thing.

Will have to go to an Engine Specific Shop.

You may be right ( probably are) but why? It’s a federally legalized adjustment to computers derate schedule.

I’ll try to get to my ford dealer later this week.