The diesel engine. Without it, goods couldn’t be transported across countries; construction/farming/mining equipment wouldn’t be as efficient, public transportation wouldn’t be as good, and so much more. While the internal combustion engine is quite literally one of mankind’s most important inventions to date, the diesel internal combustion engine takes it even further.
And even though the diesel engine has been incredibly vital to transportation and dozens of other industries, the Environmental Protection Agency, also known as the EPA, has spent the last 35 years slowly destroying the diesel engine and plans to force it out of commission as soon as possible.
You’ve often heard how EPA changes forced automotive manufacturers to change their products but rarely hear why, so it’s time we take a deep dive into the history of the EPA, the diesel engine, and what the future holds.
EPA: Good and Bad
And before we get into this, I just want to briefly mention that although most of this article will be highlighting that the EPA has destroyed diesel engines, they have done some good things in regards to limiting city pollution and improving the environment.
They’ve also done some very bad things, and in general, because they’re a branch of the US government, there is some corruption and bias within the agency, just as there is with every branch of our government.
How the EPA was Created
To fully understand how the EPA has slowly destroyed the diesel engine, we need to rewind the clock from 1963 to the EPA’s inception. Well, technically, in 1963, we saw the Clean Air Act of 1963, which was really just an extra step after the Air Pollution Control Act of 1955.
The Clean Air Act was later modified to give the Department of Health, Education, and Welfare the authority to set federal standards for vehicle emissions output as soon as 1967.
Then California, being one of the most forward-thinking states, set out its own efforts in 1967 to curb smog with the California Air Resources Board, also known as CARB. Other states were also dealing with smog issues at the time, but no one wanted to set emissions standards in place for fear of driving away automotive manufacturers.
Ultimately, this led to the Clean Air Act being modified again to prevent the states from being able to set more restrictive emissions standards than the federal government, but because California created CARB before this, they were grandfathered in and were allowed to keep CARB around, which is something that California residents are still dealing with today, and it’s something that has plagued the automotive industry with many parts needing to be CARB certified to be legal in California, but more on that later in the article.
That takes us forward to 1970, with air pollution across the US becoming a major political focus, which led to President Nixon signing an executive order to create the EPA, which also combined all environmental-related programs to a single entity. Just like before with the HEW Agency, the new EPA had the authority to set emissions standards for road-going vehicle pollution output.
For the remainder of the article, we’re going to look at changes the EPA has made in regards to diesel engines only, so we’ll be ignoring any changes they’ve made since the 1970s regarding gasoline-powered vehicles.
1980s Changes
Starting with the first change the EPA made for diesel engine emissions output, we have a new standard coming into play in 1985 that set the standard for NOx output from heavy-duty engines and particulate matter from heavy-duty diesel engines in trucks and buses.
However, carbon dioxide output for diesel engines was limited since 1974 and actually got tougher in 1979; it just wasn’t until 1985 that we say NOx output limitations.
These standards were set in 1985 but didn’t go into effect until 1988, giving diesel engine manufacturers just three years to come up with a plan to have their engines meet these new standards. Keep in mind that you don’t HAVE to meet these standards, as you could still build and sell non-conforming engines. However, you’d have to pay a pretty big fine that would more than offset any profits you generated on those non-conforming engines.
As to where those fines go and what they’re funding, it’s not exactly clear, but monetary fines are the simplest and logistically the simplest form of punishment for a company building engines that fail to meet the EPA’s standards. So although money won’t fix the environment, it’s basically the EPA’s only logical form of punishment.
Keep in mind, at this time, diesel engines were really seen in anything other than heavy-duty applications, as diesel-powered pickup trucks were really a thing. Yes, they existed, but they weren’t very popular at all because the performance frankly was pretty terrible back then.
There were also limits on smoke opacity percentage, so basically, how thick the smoke from the truck was, and this was dependent on acceleration, lug, and peak modes, with different percent opacities allowed per mode.
Then in 1987, we saw another big change for heavy-duty engines with the introduction of particulate matter limitations, which were then reduced even further in 1991 and broken apart to separate general heavy-duty engines and urban bus engines, with the bus engines being required to have even lower particulate matter output.
1990s Changes
Then again, in 1994, heavy-duty truck engines were once again forced to comply with even lower particulate matter output, which was about 50% reduced as compared to the 1991 to 1993 regulations, and to help all engines meet this new standard, we saw the introduction of low sulfur diesel fuel one year prior in 1993, which limited diesel fuel to 500ppm.
From 1994 to 1998, very minor changes to the requirements for heavy-duty engines, but that being said, in 1997, the EPA set standards that wouldn’t go into effect until 2004. These new standards were created with the goal of reducing NOx emissions output to 2.0 g/bhp·hr, which was a fairly big jump, around 50% reduced as compared to the 1998 standard.
In order for heavy-duty engine manufacturers to meet these standards, pretty much all of them introduced exhaust gas recirculation to their engines, as well as many of them also adding in diesel oxidation catalysts.
Interestingly enough, 1998 also had a handful of court issues between the EPA, the DOJ, CARB, and engine manufacturers such as CAT, Cummins, Detroit, Volvo, Mack, and more. Pretty much all of them had been caught using engine control software which improved fuel economy but increased NOx emissions output on the highway, and the EPA ultimately considered this an emissions defeat device, and all companies involved were punished with penalties and also forced to meet the upcoming 2004 standards by October 2002.
2000s Changes
Jumping up to 2006, we saw the introduction of ultra-low-sulfur diesel fuel, which was limited to just 15ppm, which is a far cry from the 500ppm and was available before the EPA came around and by 2007 fuel regulations were put in place to force ultra-low-sulfur fuel as the nationwide standard.
2007 also brought with it the standards the EPA had set back in December of 2000, with a massive decrease in particulate matter and NOx emissions output. These changes were set to be phased in from 2007 to 2010, and I’d have to suspect that window was so large because the change was so drastic that companies didn’t exactly know how to meet these standards.
Technically speaking, the NOx standards were the only part of the standards that were phased in, as the particulate matter standards were immediately enforced in 2007, and funny enough, most engines actually struggled to meet the phase-in period, which is often where we see the 2007 and 2010 standards are referred to as different standards, even though they’re the same just with ramp from 07 to 10 because of that phase-in period.
And because the 2007 standards were such a big change, this is when we saw the introduction of the dreaded diesel particulate filter, which is actually part of the reason for ultra-low-sulfur fuels introduction, as things such as DPFs and NOx catalysts are very sensitive to sulfur content and ultimately won’t work properly with high-sulfur content fuel.
2010s Changes
Jumping to 2015, we saw NOx standards massively decrease yet again, but since then, we haven’t seen any changes on the heavy-duty side of things. However, looking forward, the EPA has standards planned for 2024 and 2027 that will cut particulate matter standards in half or more.
I’d also like to quickly highlight that in 2017, heavy-duty engine and vehicle manufacturers must meet GHG emissions and fuel economy standards that became applicable from the model year 2017 and onwards, on top of all the emissions standards.
Up until this point, we’ve been looking at emissions standards for heavy-duty vehicles, which are classified as anything with a GVWR of 8,500lbs or higher.
On the non-heavy duty side, things are even more confusing with multiple tiers, which are then broken out into bins, and honestly, it’s a little outside the scope of this article, as we’re really looking more at diesel trucks and not diesel cars. That being said, many of the emissions systems that were introduced on heavy-duty diesel engines were also introduced on “light-duty” diesel engines, as the standards were generally changed on the same dates as heavy-duty diesel engine standards.
The End Consumer Pays the Price
And while I think on paper, the EPA’s efforts are a good idea, as reducing smog and pollution is a net positive for all humans, after all, we have to breathe that air to survive, and if the air is full of chemicals, it’s ultimately going to create public health issues. The only issue I have with this is that these standards have ultimately made diesel engines worse than ever.
What I mean by this is that the emissions devices that manufacturers have had to introduce to their engines are ultimately the weakest link on just about every modern diesel engine.
Exhaust gas recirculation systems are well known for struggling with stuck valves, clogged coolers, cracked coolers, and much more. Extreme examples of this include the 6.0L Powerstroke, where the EGR system causes massive issues and can literally cause catastrophic engine failure, and guess who has to pay for that when it happens? Not the EPA, the end consumer.
Then other parts like the diesel particulate filter get clogged up with time and those are incredibly expensive too. Then you have the annoying diesel exhaust fluid system, which is yet another fluid you have to regularly refill on your truck, or else your truck will stop working entirely.
And really, a lot of these systems have made diesel engines so unattractive that in industries such as transportation, we’re seeing a record number of owner-operators keeping their existing trucks on the road rather than upgrading to a newer truck with newer systems as keeping their current trucks on the road is ultimately cheaper, and their old trucks can often be more reliable than new trucks.
Then we have issues such as really old diesel engines which were designed with high-sulfur diesel fuel in mind, which now struggle to operate at 100% with modern ultra-low-sulfur diesel fuel, as the reduced sulfur content means the fuel has reduced lubricity, and that can lead to lack of lubrication across the fueling system and even more problems.
The Future of the EPA
And moving forward, we can see that these standards are getting stricter, and stricter, and stricter. And now we have President Biden signing in executive orders which sets even stricter targets for passenger vehicles, light-duty trucks, and heavy-duty trucks, all with the goal of ultimately forcing the road-going diesel engine out of existence by introducing standards that are so strict that no internal combustion engine can meet.
And even if diesel engine manufacturers were able to develop engines that could meet the future standards, what other reliability-plaguing emissions systems will be introduced, and with the engines getting more expensive to develop and construct, heavy-duty trucks will also get more expensive, which will all ultimately lead to increased prices on virtually all goods for the end consumer.
And I know what you might be thinking, okay, if diesel engines are forced off the road through emissions standards that can’t be met, what’s the big deal? All trucks will simply switch to electric or hydrogen or something else in order to stay on the road.
And while that idea is great on paper, as we’ve discussed in other articles, that requires a massive change in the country’s infrastructure, including thousands of new charging stations specifically for electric semi trucks, massive new power generation facilities, a massive uptick in lithium mining, and so much more, which ultimately won’t create a net positive on earth for literal decades unless our power generation is switched to renewable sources.
And all of that ultimately means no matter how this goes down, whether the EPA successfully fully kills road-going diesel engines or not, the end result will always be an increased cost of goods to the end consumer.
Add that on top of the existing record-breaking inflation and impending recession, and you can see a long-term disaster brewing in the near future.