There have been a lot of posts recently talking about shortages of DEF bringing many modern (2010 and newer) trucks to a halt. Let’s be perfectly clear on what DEF actually is and how it’s used in trucks (and other diesel powered vehicles). First and foremost, it is not used in the engine itself and hence has nothing to do with actually powering the vehicle. Diesel engines only need two things to run. Fuel and air. So, what is the DEF used for? Think of it as a key ingredient in the “clean up committee”. I’ll explain… Diesel engines are known to produce “particulates” (aka “soot”) as a by product of the fuel/air combustion process. Those particulates are certainly a pollutant. Some studies indicate that those particulates are carcinogenic. How bad a problem is it though? That’s difficult to answer because those studies are relatively recent and I’ve yet to find one indicating just how much you have to inhale or ingest in order to get cancer. For perspective, diesel engines have been around since 1897. Long before any studies looking into their impact on the environment were conducted. I would encourage any of my trucker friends to weigh in on their experience with the harmful effects of being around diesel engine exhaust. So, there’s a little background on DEF and why trucks “need” it. It’s the result of a government mandate requiring truck manufacturers to include on all diesel powered over the road products made since 2010. I don’t know what the requirement for diesel powered passenger vehicles is as that’s a topic for another discussion.
Before I go on, I suggest the curious reader who wants to know more about what DEF is, where it comes from, why it’s being used, etc… can read more about it: <HERE>
So, why is a shortage of an exhaust treatment chemical going to bring the trucking industry to its knees if this DEF thing isn’t needed in the combustion process? The short answer is, “computers”. The computers monitor virtually all aspects of modern trucks including the engine and the exhaust. If you read that article, you know that DEF is injected into the exhaust stream prior to going into the SCR (Selective Catalyst Reduction - clean up committee) system. In the reaction chamber, the particulates are burned into much smaller “stuff” and then released into the air. I can’t tell you exactly what that stuff is comprised of and how dangerous it is. But I do know that it is smaller, harder to see, and (supposedly) pollutes less. That is also a topic for another discussion.
I would like to bring up a couple of thoughts having to do with keeping the trucks rolling should DEF shortages occur. First, for 2010 and newer trucks, they would have to be reprogrammed and retrofitted to bypass the SCR system somehow. That would involve two things... Replacing the SCR device itself with a straight pipe. Because if it were left in place, it would clog up with unburned particulates in the absence of DEF being injected into the exhaust stream. If the exhaust can’t flow, the engine can’t run. Second, the computer would have to be either reprogrammed to ignore inputs from the SCR/DEF system monitoring components, or the sensors that provide that data would have to be jury rigged… somehow. California will probably be hit the hardest because they forbid older, non SCR equipped trucks from operating in the state. States like Oregon, for example, do not require SCR equipped trucks to transport goods on Oregon highways. So, yes… they pollute more. How much depends on how well maintained the engine is. There are lots and lots of older trucks still in use here in Oregon. Part of the reason for that is cost. A new SCR equipped truck is very expensive. Rebuilding older trucks is much more feasible. That is as long as the state government doesn’t get too crazy and begin to mandate “cleaner” trucks.
So, what is “the government” going to do when goods can’t be shipped due to lack of DEF? Are they going to place a moratorium on emissions controls? Are they going to allow technicians to bypass SCR systems? Are states like California going to relax their requirements and allow older, non-SCR trucks to move the freight? If the early reports are accurate and the USA is as dependent on foreign suppliers of urea (key ingredient in DEF) as I’ve read, we’re going to have to do something in order to move the freight. Or enterprising entrepreneurs are going to have to step up and start making the urea here in the US. Based on what I’ve read, making urea ain’t that hard. It does require natural gas. Something the US has a lot of. Whether we’ll be allowed by the Biden administration to use it or not, remains to be seen.
The future ain’t lookin’ too bright right now. Just a friendly reminder: The mid term elections are right around the corner. Do your homework and vote wisely and help make America great again.
Here’s a nice article outlining the current situation worldwide: <LINK>