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EPA Set to remove DEF engine derate...

Posted on 8/12/25 at 12:58 pm
Posted by BoostAddict
Member since Jun 2007
3132 posts
Posted on 8/12/25 at 12:58 pm
LINK

Awesome! Stupid chit has left me stranded in the middle of nowhere multiple times because of a stupid chinese made sensor.

If you're unfamiliar with derate... if there is a problem with the DEF or SCR system on your diesel powered vehicle or equipment, you get 4 hours of run time before your truck will only go 5mph... Even if the system is actually functioning properly.
Posted by bad93ex
Walnut Cove
Member since Sep 2018
33565 posts
Posted on 8/12/25 at 12:59 pm to
We are healing!
Posted by DownshiftAndFloorIt
Here
Member since Jan 2011
70784 posts
Posted on 8/12/25 at 1:07 pm to
frickING

A

RIGHT

You want to get people to quit deleting trucks, this is by far the biggest single step you can take.

Mine almost stranded me 20 miles away from the highway, in a blizzard, and below 0*F. The shite is dangerous. Most people have no problem at all with buying a jug of DEF every now and then but when we start talking about literally stranding people thousands of miles from home with shite like this people get mad.

Will Cummins get their $2B fine refunded?
Posted by RanchoLaPuerto
Jena
Member since Aug 2023
1734 posts
Posted on 8/12/25 at 1:11 pm to
quote:

DEF


At first I read that as “DEI” and was very confused.
Posted by Horsemeat
Truckin' somewhere in the US
Member since Dec 2014
15060 posts
Posted on 8/12/25 at 1:13 pm to
DEF needs to be scrapped completely.
Posted by DownshiftAndFloorIt
Here
Member since Jan 2011
70784 posts
Posted on 8/12/25 at 1:17 pm to
quote:

DEF needs to be scrapped completely


Nah. It's not a bad thing at all. It's a lot simpler than EGR and much more effective. If you want to knock NOx out of the exhaust stream, aftertreatment is the way to do it.

The problem is the protections, interlocks, derates etc associated with the EPA being a bunch of dickheads.
Posted by member12
Bob's Country Bunker
Member since May 2008
32998 posts
Posted on 8/12/25 at 1:46 pm to
MPG will climb too.
Posted by member12
Bob's Country Bunker
Member since May 2008
32998 posts
Posted on 8/12/25 at 1:49 pm to
quote:

EPA’s new guidance to engine manufacturers will reduce derating — an automatic trigger forcing the engine to operate at a reduced capacity far below its capability — and increase the amount of time operators have to secure DEF and refuel while retaining the environmental benefits for farm equipment and trucks.


Posted by Bawpaw
Member since May 2021
1536 posts
Posted on 8/12/25 at 1:51 pm to
The same group that pushed for DEF didn’t account for how much cardboard and plastic is now in landfills.
Posted by TroyTider
Florida Panhandle
Member since Oct 2009
3974 posts
Posted on 8/12/25 at 1:54 pm to
quote:

The same group that pushed for DEF didn’t account for how much cardboard and plastic is now in landfills.


Do they ever?

Posted by SWLA92
SWLA
Member since Feb 2015
4379 posts
Posted on 8/12/25 at 1:54 pm to
That group didn’t care about plastic and cardboard. They only cared about lining their pockets. It was all a scam and we pay the prices for our government pushing this BS. I’ve lost countless hours because of equipment derating. There’s a special place in hell for those that pushed this DEF crap.
Posted by DownshiftAndFloorIt
Here
Member since Jan 2011
70784 posts
Posted on 8/12/25 at 1:55 pm to
That sure does read like they aren't actually changing anything except delay derate for a DEF level fault, which is literally the only one that occurs solely due to operator stupidity, and is the only one that I am 100% ok with the engine derating for. Making stupid decisions should have stupid consequences.

That doesn't do anything for getting a derate warning because a NOx sensor went out of range or because the DEF quality sensor went haywire, which are where the real problems with aftertreatment systems are.

People who want aftertreatment to go away have zero understanding of how it works or what it accomplishes. You get rid of DEF, you are back to shitloads of EGR, horrible fuel economy, and busted up garbage engines like we had prior to 2008. Do you REALLY want 11mpg and worn out engines at 100k miles so you don't have to buy DEF?
Posted by wallowinit
Louisiana
Member since Dec 2006
16978 posts
Posted on 8/12/25 at 1:56 pm to
I VOTED FOR THIS!!!
Posted by Turnblad85
Member since Sep 2022
4182 posts
Posted on 8/12/25 at 1:59 pm to
A buddy has a small concrete pumping business in Dallas. A couple years ago he upgraded to a brand new boom truck ($500k). A few months in he had a def sensor issue. Thing was a beached whale until they could get the backordered sensor. Jobs cancelled, employees still on payroll, bank still wanting their payments.

Talk about kneecapping the American economy.
This post was edited on 8/12/25 at 2:01 pm
Posted by DownshiftAndFloorIt
Here
Member since Jan 2011
70784 posts
Posted on 8/12/25 at 2:25 pm to
You oughta see the implications of having this stuff installed in a ship.

But, we really need to just accept that DEF is here to stay. It isn't going away. What we can hope for is the derates and fines and ridiculous controls restrictions to be relaxed.
Posted by ozktgr
North Arkansas
Member since Mar 2020
390 posts
Posted on 8/12/25 at 2:29 pm to
EPA Chief, Lee Zeldin, announced two weeks that they plan on rescinding the Endangerment Finding from 2009. This could open the flood gates on how we deal with emissions. I believe the 45 day window for public comment ends in September

EPA Article
This post was edited on 8/12/25 at 2:39 pm
Posted by Turnblad85
Member since Sep 2022
4182 posts
Posted on 8/12/25 at 2:30 pm to
quote:

accept that DEF is here to stay


I admit I'm not very knowledgeable on the diesel systems. One thing I would like to know, does a Def system really result in cleaner air?

If so, that makes the extra expense and trouble more digestible. I like clean air. I like for my kids to breath clean air.
Posted by beerJeep
Louisiana
Member since Nov 2016
37661 posts
Posted on 8/12/25 at 2:31 pm to
Nothing like forcing people to put piss in their car for emissions.
Posted by DownshiftAndFloorIt
Here
Member since Jan 2011
70784 posts
Posted on 8/12/25 at 2:35 pm to
quote:

One thing I would like to know, does a Def system really result in cleaner air?



I guess it depends on what you define as pollutants. The SCR system (which is what the big can on the exhaust pipe is that consumes DEF as a reductant) reduces free nitrous oxides in the exhaust stream to negligble levels. The DPF system (the smaler can in the exhaust pipe which is a catalyst/filter) dramatically reduces particulates in the exhaust (soot) by extremely dramatic levels.

My truck has 100k miles on it and you can rub your finger on the inside of the tailpipe and it won't turn black. I don't remember the exact numbers but current "emissions" of diesels (NOx and PM) are something like 15,000% lower than a pre-2002 non-emissions controlled diesel engine.
Posted by DownshiftAndFloorIt
Here
Member since Jan 2011
70784 posts
Posted on 8/12/25 at 2:37 pm to
quote:

that they plan on rescinding the Endangerment Find from 2009




Yea, that is very big news with potentially significant implications.

My only issue with our emissions standards is that we kneecap ourselves economically when China and India have no such regulations and can pollute enough to more than offset the improvements the US and Europe have made in the past 30 years.

If we are really serious about all this save the planet crap, we should be sanctioning the shite out of China and India.
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