To say that the on-road emissions of a given vehicle exceed the allowed emissions standard or the emissions measured during dynamometer tests does not mean necessarily that “cheating” is the reason.

In the VW case, the explicit effort to defeat the emissions control equipment was an obvious and deliberate evasion of the relevant emissions regulations.

Consider instead a recent case involving Hyundai and Kia, settled by consent decree in November 2014; it resolved allegations that its fuel economy estimates were biased upward, as well as alleged violations of the Clean Air Act created by sales of more than one million vehicles that will emit about 4.75 million metric tons of greenhouse gases in excess of the emissions that the manufacturers certified to the EPA.

Nonetheless, the VW scandal reportedly has yielded a series of other investigations. Perhaps actual cheating will be discovered, although no such evidence yet has been made public. And there is a case to be made that some due diligence on the part of US regulators is appropriate, in that an absence of such effort could be predicted to yield an erosion of the emissions regulatory framework, and environmental quality more centrally.

Read the full article on emissions regulatory crackdown by Benjamin Zycher at American Enterprise Institute