I had the opportunity to work with a major diesel engine manufacturer in trying to meet the clean air regulations and have to say that those mufflers, which are actually particulate traps, are as reliable as the weather forecasters. It doesn't take much to ruin them, they don't always work as advertised, and sometimes can fail to the point of damaging the engine itself.
When one considers how clean trucks have become, this latest hit against them smacks of another run against our freedoms. There comes a time when clean enough is good enough, and the fact that most motor vehicles are 96% plus cleaner than they were 30 years ago should be enough.
We're going to see owner-operators buying a lot of 2008 and older trucks for quite some time. In addition, these newer motors get worse fuel economy compared to the older ones.