The modern diesel engine is a marvel of engineering. You could walk down to your local Ford dealer and drive out in a pickup truck that has 500 horsepower and 1,200 lb-ft of torque right from the factory. However, that truck will also be laden with complex emissions systems designed to make all of that power easier on everyone’s lungs. These systems are sometimes problematic and expensive to repair. The U.S. Environmental Protection Agency wants to change that by rolling back diesel emissions rules, and, if several members of Congress have their way, making diesel truck emissions deletes legal on the federal level. One of the rollbacks is already happening. Let’s take a look.
This news comes to us in two parts that happened roughly at the same time. On the federal level, U.S. Environmental Protection Agency (EPA) Administrator Lee Zeldin announced that, in an effort to eliminate limp modes and power derates from emissions system failures, the EPA is no longer requiring Diesel Exhaust Fluid (DEF) urea quality sensors on any equipment powered by diesel engines.
At the same time, U.S. Representative Mike Collins (R) of Georgia has introduced the Diesel Truck Liberation Act into the House. Companion legislation of the same name has been proposed in the Senate by U.S. Senator Cynthia Lummis (R) of Wyoming. The Diesel Truck Liberation Act calls for a stunning unraveling of emissions regulations. The proposed Act says that, if enacted, it would remove the federal government’s power to regulate motor vehicle emissions. Then, it goes a huge step further, saying that any federal law against the tampering or removal of emissions equipment would be repealed.
Both of these actions follow earlier announcements regarding diesel emissions. In August 2025, EPA Administrator Lee Zeldin told manufacturers to stop forcing trucks into immediate limp modes for low DEF levels. Back in January 2026, the U.S. Department of Justice said that it would no longer pursue criminal charges against those found tampering with vehicle onboard diagnostics systems. In February, the EPA said that it was seeking to hold manufacturers accountable for foisting unreliable DEF systems on consumers. It was around that time when the EPA also openly considered just getting rid of emissions-related limp modes entirely.
So, these two new updates are really only a continuation of what we’ve been seeing in this current presidential administration. In essence, multiple parts of the federal government are trying their hardest to remove as many regulations from diesel engines as possible. But why? What’s with this obsession with DEF and legalizing emissions deletes?
Modern Diesel Emissions Systems Do Hard Work
What engineers have achieved with modern diesel emissions systems is impressive. Let’s go back to that Ford Super Duty that I talked about in the opener. Not only can the top spec of that truck tow a 40,000-pound trailer with relative ease, but it will do so without black smoke and without a pungent smell. You can walk right up to the exhaust, take a big whiff, and not detect the smell of diesel.
If you haven’t read my previous coverage on diesel emissions and their regulations, here’s a quick review of how far we’ve come, from my previous coverage:
According to Diesel Power magazine, the implementation of diesel emissions equipment was gradual. Back in the 2000s, buyers of trucks found an Exhaust Gas Recirculation (EGR) system in their engine bays. EGR systems reduce emissions by recirculating a portion of an engine’s exhaust back into the intake. Even your modern gasoline-fueled car has an EGR system. Next came the Diesel Particulate Filter (DPF), which is an exhaust aftertreatment system designed to trap particulate matter before it leaves the vehicle.
As emissions requirements demanded diesels to run even cleaner, emissions equipment evolved. The Selective Catalytic Reduction (SCR) was an important advancement in diesel emissions reduction technology. 2010 model year heavy diesels have SCR to meet the EPA’s strict regulations. Any light-duty diesel that didn’t already use SCR phased in its use during the early 2010s.
SCR uses an aqueous urea solution, DEF, fired into the exhaust to convert NOx into nitrogen and water. DEF is 32.5 percent formaldehyde-free low biuret urea and 67.5 percent deionized water.
The diesels found in today’s passenger vehicles, pickup trucks, semi-trucks, and farming equipment use multiple methods to ensure what comes out of the tailpipe is cleaner. The use of SCR has been reported to reduce nitrogen oxide (NOx) emissions by as much as around 90 percent.
Engine Derates Because Of DEF Issues
DEF system tanks have to be periodically refilled. In the past, not refilling your DEF system led to a torque derate or limp mode. A derate or limp mode also occurred if a sensor failed and your truck was no longer able to tell that there was DEF in the tank, or if the truck incorrectly believed that you had diluted the DEF.
This has been an annoyance for many truckers, pickup truck owners, and farmers because not every diesel engine manufacturer has implemented this technology in a reliable manner. The aggravating thing is that you could have an entirely full DEF tank and still go into limp mode because of a sensor failure. If the diagnostics system believes the issue to be severe, the limp mode could be as bad as leaving the engine at idle speed.
This was the impetus for the EPA establishing a grace period for DEF-related issues, be it an empty tank or faulty equipment. A semi-tractor operating under the new rules would be able to drive 650 miles or 10 hours before a 15 percent reduction in torque. A pickup truck will enter a 45 mph limp mode 4,200 miles or 80 hours after the detection of a DEF issue. Click here to read my previous story for more about the grace period.
The EPA Wants To Eliminate A Failure Point
Now, the EPA is taking this idea even further. What if your truck couldn’t go into limp mode because the failed sensor just didn’t exist anymore? On March 27, the EPA announced:
Today, at the White House Great American Agriculture Celebration, President Trump announced another decisive action U.S. Environmental Protection Agency (EPA) Administrator Lee Zeldin has taken to address nationwide concerns from farmers, truckers, motor coach operators, and other diesel equipment operators regarding Diesel Exhaust Fluid (DEF) system failures by removing the DEF sensor requirement for all diesel equipment. EPA understands that sudden speed losses and shutdowns caused by DEF system failures that compromise safety and productivity are unacceptable and problematic. While EPA continues to pursue all legal avenues to address Americans’ complaints, today the agency is implementing another part of Administrator Zeldin’s plan to help keep American operators from losing days in the field or on the road because of faulty DEF systems. EPA’s new guidance, which removes DEF sensors, will provide immediate relief and save billions of dollars in repairs and lost productivity. According to the U.S. Small Business Administration (SBA), this guidance will save farmers $4.4 billion a year and this action will provide $13.79 billion a year of savings to Americans.
[…]
“Failing DEF systems are not an east coast or west coast or heartland issue; it is a nationwide disaster. I have heard from truck drivers, farmers, and many others complaining about DEF and pleading for a fix in all 50 states I visited during my first year as EPA Administrator,” said EPA Administrator Zeldin. “Americans are justified in being fed up with failing DEF system issues. EPA understands this is a massive issue and has been doing everything in our statutory power to address this. Today, we take another step in furthering our work by removing DEF sensors. Farmers and truckers should not be losing billions of dollars because of repair costs or days lost on the job.”
The EPA says that, following its February promise to hold manufacturers accountable for emissions equipment failures, 11 out of the 14 diesel engine manufacturers that represent 80 percent of the diesel market have provided data about system failures and warranty claims. This new action is based on the preliminary findings from this data.
According to the EPA, one of the most common failure points in DEF systems is the Urea Quality Sensor (UQS), which detects if the DEF is diluted or is otherwise not up to standard. If this sensor fails, the diesel engine may derate. This sensor is typically found somewhere in the DEF tank. So, the EPA is just getting rid of this sensor entirely and wants to have manufacturers switch to nitrogen oxide (NOx) sensors.
Here’s how the sensors can be used to detect DEF quality issues, from the EPA:
These strategies monitor NOX concentration in the exhaust stream and determine SCR catalyst efficiency by measuring changes in NOX across the catalyst. Significant deviations in NOX conversion across the SCR catalyst from the expected or modeled conversion rate can be an indication of poor DEF quality. In most applications, NOX sensors have been able to detect poor DEF quality for many, but not all, DEF dilution scenarios.
The EPA says it’s still studying the data from the diesel engine manufacturers to come up with permanent fixes. But for now, it thinks that just getting rid of the sensor entirely will save farmers $4.4 billion a year and “$13.79 billion a year of savings to Americans.”
What is notable is that, at least for now, the EPA’s thought about just getting rid of derates entirely hasn’t happened. Also, even with the removal of the UQS, you’ll still be required to use DEF, and your truck will still have to be equipped with its emissions system.
Legalizing Diesel Deletes?
But there’s another line of thinking among some minds in the U.S. government right now. There’s a more aggressive idea out there to just take diesel emissions regulations out of the control of the federal government while also legalizing emissions deletes.
On March 26, U.S. Representative Mike Collins (R) of Georgia introduced the Diesel Truck Liberation Act. In his press release, the Representative said:
Today, Representative Mike Collins (GA-10) introduced the Diesel Truck Liberation Act, legislation that will stop the Environmental Protection Agency (EPA) from criminalizing family farmers and truckers through federal emission mandates that do little to help the environment while driving up costs for Americans.
[…]
“American truckers and farmers are the backbone of this nation, but the EPA has treated them like criminals for maintaining their own equipment,” said Rep. Mike Collins. “The Diesel Truck Liberation Act codifies the work of EPA Administrator Lee Zeldin to free farmers and truckers from the radical federal emissions mandates of past Administrations and end the bureaucrats’ war on the working class. I am proud that we have an administration focused on delivering for the working class and putting common sense first.”
Alright, so what does this Act propose? The press release keeps it simple:
Federal agencies like the Environmental Protection Agency (EPA) have piled emission mandates onto diesel trucks and equipment in the name of environmental stewardship. However, these mandates have done little to improve the environment while saddling American workers with ridiculous costs to repair and update vehicles. Truckers and farmers who cannot afford such updates are forced to sideline their vehicles, leave the business altogether, face penalties, or even go to jail.
The Diesel Truck Liberation Act is common sense legislation that looks out for the American worker by:
– Stopping federal agencies from requiring manufacturers to install or maintain emissions control devices or onboard diagnostic systems.
– Removes the EPA’s authority to enforce Clean Air Act requirements related to vehicle emission controls.
– Protects individuals sued or prosecuted under federal law for tampering or improving emissions equipment.
– Codifies the work of Representative Mike Collins and EPA Administrator Lee Zeldin to ensure that no matter who is in the White House, truckers’ and farmers’ livelihoods are protected.
There is companion legislation in the Senate. S.3007 – Diesel Truck Liberation Act of 2025 was introduced by U.S. Senator Cynthia Lummis (R) of Wyoming. Rep. Collins is joined by cosponsors Rep. Anna Paulina Luna (FL-13), Rep. Barry Moore (AL-01), Rep. Dave Taylor (OH-02), Rep. Harriet Hageman (WY-AL), Rep. Mike Ezell (MS-04), and Rep. Tony Wied (WI-08). Meanwhile, Sen. Lummis has support from Sen. Dan Sullivan (R) of Arkansas and Sen. Pete Ricketts (R) of Nebraska.
The companion bill from Sen. Lummis states:
(a) In general.—Notwithstanding any other provision of law, including title II of the Clean Air Act (42 U.S.C. 7521 et seq.), no Federal law (including regulations and Executive orders) may require a manufacturer, importer, or distributor of motor vehicles or motor vehicle engines to install, certify, or maintain any emissions control device or onboard diagnostic system on any motor vehicle or motor vehicle engine.
(b) No authority.—The Administrator of the Environmental Protection Agency may not promulgate or enforce any requirement under the Clean Air Act (42 U.S.C. 7401 et seq.) (including a regulation promulgated under that Act) or any other Federal law (including regulations) that requires the installation or maintenance of emissions control devices or onboard diagnostic systems on motor vehicles or motor vehicle engines.
(c) No liability.—Notwithstanding any other provision of law, no person or entity shall be subject to civil or criminal liability under any Federal law (including regulations) for the manufacture, sale, importation, purchase, use, or modification of a motor vehicle or motor vehicle engine that does not contain an emissions control device or onboard diagnostic system.
(d) Repeal of regulations.—Any regulation promulgated under the Clean Air Act (42 U.S.C. 7401 et seq.) or any other Federal law related to the installation, modification, or removal of emissions control devices or onboard diagnostic systems on motor vehicles or motor vehicle engines shall have no force or effect.
(e) Vacatur; expungement.—With respect to any of the conduct described in this section for which criminal or civil liability has attached—
(1) any criminal penalty of imprisonment shall be vacated; and
(2) any record of a finding with respect to that criminal or civil liability shall be expunged.
That’s a big deal. Put simply, these senators believe that the federal government shouldn’t be able to regulate emissions and cannot do anything if you tamper with emissions equipment. This bill makes the EPA’s current actions look tame in comparison.
If you enjoy the thought of hazes of smog not returning to American cities, the good news is that there’s been a lot of talk about the Diesel Truck Liberation Act, but not a whole lot of progress. On October 14, 2025, the day Sen. Lummis filed the bill, the bill in the Senate was referred to the Committee on Environment and Public Works, where it remains today.
Meanwhile, Sen. Lummis and Sen. Dan Sullivan also introduced the Cold Weather Diesel Reliability Act, which seeks to eliminate DEF-related derates in temperatures below 32 degrees and exempt vehicles that operate north of 59 degrees north latitude from being derated. This bill recently had a hearing at the Committee on Environment and Public Works, but has otherwise not gone very far yet.
What Does The Future Of Diesel Look Like?
The EPA says its move to eliminate DEF sensors is being praised for improving diesel reliability and saving Americans money. Of course, we’ll have to wait and see what will actually happen in the real world.
As for the Diesel Truck Liberation Act, it could effectively erase the advancements in diesel emissions in America and also set our country behind the rest of the world. It’s also unclear what would happen on the state level. Would California still have its own regulations?
But perhaps we’ll never need an answer to these questions as both versions of the Diesel Truck Liberation Act have yet to go very far. Even with extremely high diesel prices, it’s not clear if there are 60 senators willing to push this forward.
I remain a huge fan of diesel power and would even get excited if some company sold a diesel-powered car in America again. However, the reason why I can enjoy a clear look at the skylines of America’s great cities is because of the advancements in reducing vehicle emissions. Maybe the answer isn’t to get rid of emissions systems, but to make them more reliable!
Top photo: RAM/DepositPhotos.com
Lawmakers?nope…F&*#ing Republicans Want To Make Diesel Truck Emissions Deletes Legal And Remove Emissions Rules
Fixed it for you.
Anyone who supports this need to spend some time around actual diesel “coal-rolling” trucks for awhile.
How about we stick all the lawmakers who support removing all diesel regulations, to have to spend an hour in an arena to watch a truck show put on nothing but fully deleted diesels?
Good. These trucks have been choked to death and regulated into complete unreliability. It’s about time we take some steps back.
As has already been said, this bill is almost certainly going nowhere so it is probably not worth discussing.
However, anyone supporting diesel emissions repeals should be VERY careful about what they wish for. Diesel emission laws were enacted for a reason. The benefit is obvious if you watch an old diesel truck pull away from a stop sign – old diesels put out visible, nasty emissions. New diesels don’t. The difference is something regular people notice. Diesel emissions might have been a greenie issue when the laws were passed, but now that we are all used to visibly better air, it won’t stay that way.
Semi-rhetorical question: is it really a good idea to eliminate highly effective, but mildly inconvenient, emissions laws when everyone who breathes will notice the change?
Administrations will change, and policies will change with them. I wouldn’t count on the repeal merely being repealed by a future administration – even stronger diesel regulations are likely the end result. It may seemed farfetched with trump in office, but it doesn’t strike me as impossible that non-commercial diesel trucks could be effectively banned, or taxes on diesel and diesel vehicles could be greatly increased. This is a Pandora’s box that should stay closed, even if it the current administration might allow us to open it.
I really like diesel trucks (and own one) and want them to continue to be available. If I have to deal with the mild inconvenience of DEF and the moderate expense if/when my emissions system breaks to ensure diesel trucks are still around, it seems like a small price to pay.
let’s bring back raw sewage and the black plague as well while we’re just doing things that are bad for the general population.
Don’t give them any ideas! RFKJr has already brought back measles…
I was behind an older, beat up truck this morning in traffic. My first thought on smelling the exhaust was “smells like someone’s project, I kinda miss having an old car that had a bit of a smell”. After only a few minutes, though, my head was hurting and I was nauseated.
So….Yeah I’m totally in favor of emissions regulations.
I was born and spent the majority of my years in Los Angeles County. I lived — though not happily — through endless brown days, “smog alerts” and the smell of ozone on hot days.
I for one approve of emissions standards in general. Granted, some of the slapped-on “fixes” by car manufacturers in the early days were horrible, negatively affecting fuel economy and making cars run like crap. I haven’t forgotten the rotten-egg smell of my first catalyst-equipped car, either.
But, over the years, air quality in L.A. improved dramatically, as has the transparency of emissions controls. One can actually breathe there without feeling as if they have inhaled a pack of unfiltered Camels.
So, on the whole, I support emissions controls as they have evolved, even if I also am in favor of passing Leno’s Law so that classic owners don’t get burned by the state of California, which runs second only to North Korea in its draconian law enforcement.
I didn’t live through the pre-emissions era, but it sounds kind of miserable.
I recall reading a study from the early ’70s that showed that spending an hour in traffic on an LA freeway was enough to raise your blood carbon monoxide saturation to around 10-15%. For reference, normal is around zero and people who chain smoke cigarettes can get up to around 10%. So breathing the air in LA actually was like chain smoking unfiltered Camels.
Further, saturations above 5% can cause individuals with heart disease to have potentially fatal arrhythmias, with a much greater risk for saturations over 10%. So basically, some individuals were at risk of dying if they got stuck in a traffic jam in early ’70s LA. I’ve heard traffic in LA is murder, but it seems like that was more literal in the past.
So yeah, I’m a supporter of emissions laws (I also agree with Leno’s law, though – classic cars driven for fun aren’t going to cause detectable changes in air quality).
What are these people thinking?
They aren’t capable of thinking.
The whole issue is that there is no rational thinking within the current administration. All they can think about is trashing the system for their own financial gain without regard for how it will hurt everyone long-term. Emissions regulations prevent dude bros with lifted trucks from choking out bicyclists and protesters that they don’t agree with by rolling coal past them. Those not in full lock-step with this insane cult of personality see how there are vast negative consequences to their actions, but of course the American people are apathetic to listening to the voice of reason, so we are stuck with a president who shits his own pants in the Oval Office because he promised a pack of lies that gullible voters lapped up.
Not sure what pisses me off more. These mouth breathers that are doing exactly the stupidest possible thing at every turn or the eventual Democrat that will one day take over and act like just adding a single word to established law is the hardest thing in the world while these chodes just got to do whatever the hell they wanted.
Hey, we’re all gonna be rolling coal soon anyways. (do to $10gal gas prices) I bet you’re now glad they didn’t shutdown the coal mines.
If we could make sure that only Lee Zeldin and his odious ilk were sucking in the noxious brodozer fumes I’d be all for it. Unfortunately we all get to enjoy the smog. Fuck MAGA and anybody who associates themselves with this retrograde movement.
A lot of hate in these comments.
I, for one, would be pretty pissed if my vehicle/tractor/whatever bricked itself because of the failure of a non-essential sensor. If the performance of the catalytic converter in your car falls below threshold, you get a check engine light. It doesn’t just shut off.
Bob.
It’s ok to hate stupid.
And the stupid shit that is proposed by the same…
Maybe a small glimmer in all of this is the sky-high diesel prices might discourage a small group of people not to buy a diesel in the future (or to drive less) – reducing the number of coal rolling trucks on the road.
I hate when environmental laws work so well that people do not realize they are working and how well they have worked so people think they are not necessary.
I also hate “the tragedy of the commons” that lets people trash our shared resources like clean air, water and public lands.
FFS This administration is trying to make it the 1950 over again but without the tax rates and more oligarchs.
“When was the last time someone caught Polio? Checkmate, vaccines don’t work”
more like 1939 I think
Elections have consequences.
Eventually the Orange Turd and his congressional minions will die, or be removed.
And eventually this country will wake up to the levels of non stop bullshit since 2016, and sanity may somewhat return, maybe…
I grew up as a kid with brown haze being called normal.
It sucked bigly. Bigly I say.
At this point all we can do is hope for someone with actual brain functions to take over this shit show.
Can’t come soon enough though.
Thank you. Yes as an asthmatic kid in the 1970s the air hurt.
We’re in a cold civil war and I don’t think this ends without a collapse.
Let them sit in stop an go traffic with several diesel pickups next to them for a while
What’s with the headline? My brain hurts….
Lawmakers Want To Make Diesel Truck Emission Deletes Legal And Remove Emissions Rules
I fixed it….
Already fixed it only minutes after publishing! I guess it takes a few more minutes to change over. I think we collectively had a brain fart with the original hed.
Ugh, and the fixed headline of the fixed headline didn’t post. Trying again.
Thanks. I thought it was just me who had to spend 3 minutes to understand the title
Wonder if The Diesel Bros in Utah will sue to get their fines back?
Also please add that the new Gas injection system like the DEF is not required. that was/is a nightmare waiting to happen on F150’s that got it recently.
We are living in the worst timeline.
We get vaccinated and then the parents who never experienced the diseases they were vaccinated against choose not to vaccinate their children.
We get smog under control through emissions controls and people who never experienced it decide it’s fine.
Sorry Gen Z and Alpha. We didn’t learn from history and are doomed to repeat it.
This is a bad idea, just in case that isn’t clear, but dead-end bills get introduced all the time, and a few backbench congresspeople introducing something does not mean “The US” wants to make deletes illegal.
That’s all the feedback I need to go with an alternate headline! My alts lost in the headline discussion for “The US”. Check it out now!
Good change, thanks!
One minor point of order – lawmakers (to be a bit flippant about it) don’t really want or even care about the subject matter of the legislation they introduce. If truth in advertising applied here, that would read “Lobbyists”.
Now that’s cynicism I can get behind! But since lawmakers are slapping their names on this, it’s fair to point it out, I think.
55 years of the EPA slowly making progress and making our air and water safe, just to be undone in a few short months by this administration.
the EPA of this admin once again going completely against what it’s named for.
We must have missed the Executive Order renaming it the Environmental Perdition Agency.
I am likely in the minority here, but good? Let the states/counties dictate their own emissions regulations.
This would mean that people who bought a diesel truck would not be legally able to drive it into a neighboring state. There’s a reason things are regulated at the federal level.
To clarify my point above, all new cars should be sold new with a federally dictated emissions system. How it is tested from time to time should be dictated by the states and counties (ex: CARB testing in CA). If a farmer takes off the emissions equipment from his John Deere tractor in rural Iowa for reliability purposes (he’s not doing it to purposefully roll coal), I don’t see why the federal government should intervene.
Joe Dirt modifies his truck legally in one state. That means it could be illegal for him to drive it in another state. Realistically, how is the 2nd state expected to enforce that?
I mean, it is still a thing that cars must have California emissions stickers on them to register them in California. it was not that long ago that there were clear differences and you could get cars registered in say Utah, or Texas if you are military, driving 90% in California, but not be technically legal. most these days are just legal everywhere now that the companies have been able to figure out how to get past some of the early cost and research hurdles. It is when the timing is tough that we get crap like Lean Burn Carbs, retarded ignition, and 2 barrel carbs all in the name of efficiency while the reality was oversized venturi’s at low speeds ineffective timing and lean air fuel ratio’s causing damage to engines resulting in oil consumption and reduced fuel economy at light to part throttle.
Good thing that is still supported and enforced by the Federal government! Oh wait….
The President says his actions “will kill the California mandates forever, and they’re never coming back.”
Allowing a state to regulate emissions is terrible horrible idea. California proved this.
This! It seems like the C.A.R.B. just comes up with stuff out of a hat. They are the original Karen’s of the world.
Have either of you lived in places with terrible air pollution? The Los Angles Basin air was a disaster. CARB and California pretty much fixed it. Why not get rid of littering laws so I can just dump my garbage out on the side of the road by the river? Emissions rules are the equivalent of rules that keep us from dumping our garbage in the woods.
We all have to breathe the same air.
The air in a big city is very different from the air in many rural areas.
You remember when acid rain was killing lakes in the Adirondacks? That acid rain was a result of air pollution from mid west power plants.
The idea that air just stays in place, is silly.
Indiana leads the nation in toxic pollution emitted per square mile. We all have to breathe pollution.
Not only are you in the minority, you’re in the wrong.
Why should a black cloud belching redneck piece of shit pollution machine be legal on one side of an imaginary line? What happens when the wind blows, or they cross that line? Fuck everybody else, I guess, cause some regressive morons think that by catering to coal rolling jackoffs and bringing back smog they’ll get another 2/4/6 years in office. I hope they have to breathe those terrible, coal-black clouds on the House and Senate floor. I hope someone sits outside their house and rolls coal right in their driveway. I hope they get real nasty lung cancer specifically and exactly from this. I hope a biopsy finds diesel particulates right down in the tissue.
Oh, wait. Is it bad for me to say those things out loud, even though that’s precisely what they’re trying to legislate into existence, wrapped in a veneer of subsections and article numbers and feel-good jingoistic pseudo-Americana bullshit?
I doubt he will be in the minority, at least in the number of people who care enough about it to vote either way. There is a difference between coal rollers and those that just want their Diesel stock, running at top fuel efficiency and last as long as possible between breakdowns. EGR buildup in a poorly designed system along with Regen cycles affecting fuel economy is a negative thing.
I love this plan! It isn’t as if states share the same air, right?
That’s a horrible idea.