I work in this industry, so I've been following it from the start. I've run test cells and written software to analyze the results from the emissions cycles that the government uses to validate the emissions compliance. I have worked around and for a very large diesel engine manufacturer who I am convinced does not cheat on this test. You'll understand why, below.

I recently leveled-up my career, and I now work with the person who originally setup such testing at this manufacturer, and one of the two people who literally wrote the spec, which is one of the most thorough technical documents I've ever laid eyes on. These are 2 of the highest-caliber engineers I have ever met in my 25-year professional career, both in terms of intelligence and capability, and in terms of integrity and trustworthiness.

This quote from the article pisses me off: "What I understand now is that the people we entrusted with the power to protect us essentially decided not to bother. Instead, they have allowed carmakers to spew whatever they want into our air." Really?! The government commissioned the spec. The government mandated that engine makers make their engines comply, and validate this compliance with internal testing. The government then paid independent testers to validate the manufacturer's results.

Excuse me, but what more did the author expect the government to do? The regulators entrusted this process to expert engineers, and expert testers. Did the author expect people who could invent the spec and create a test cell to do the validation to go to work for the EPA directly, and do the paperwork, instead of the engineering? Did they expect them to escrow the code, and validate that there was no cheating? Possible, but, again, you're asking a very specific skillset to give up DOING, and instead REGULATING, and that doesn't usually work.

The fault of this scandal lies -- of course -- with the manufacturers, but the fault also lies with the legislators. To control diesel engine emissions within the spec requires an array of very expensive after-treatment components. That can work in the class-8 heavy trucking industry, but you can't even fit it into a passenger car, let alone make it affordable at gasoline car prices. To think that cars could use diesel engines, be cost-competitive with gasoline-fueled alternatives, AND pass the ridiculously-low emissions standards that lawmakers have arbitrarily decreed was simply wishful thinking.