I’d advise folks to check out the article, there are some possible explanations that need to be ruled out. Still, I’m leaning towards “there is probably some level of deliberate opacity here to look better,” which is not a good thing to do at all.

“it appears to be within the bounds of the regulator.”

This is the EPA’s fault, full stop. If regulators want to rein in this behavior, they need to fix the bugs in their tests.

I’m so happy with my car I’m unwilling to grab a pitchfork.