VW fails high school chemistry?

Apparently, a new scandal is breaking out at Volkswagen: they have understated carbon dioxide emissions for eight hundred thousand cars.  This isn't much like the nitrogen oxide emissions scandal, where there at least was software modifying the engine's operation to reduce emissions--there was at least some cleverness in that case.

In this case, we have a simple equation; minus soot, unburned fuel, and carbon monoxide (all of which are minimized in a well designed modern engine), one gallon of gasoline has about five pounds of carbon which are changed into a bit above 18 pounds of carbon dioxide.

So if you've got a reasonable estimate of mileage, you can get pretty close to the actual carbon dioxide emissions simply as 18/MPG pounds of carbon dioxide per mile.  Diesel, maybe 20/MPG pounds /mile.  So what we have here is that not only did VW's engineers fail to make this simple calculation, but so did the EPA, European regulators, Asian regulators, environmental groups, car magazines, and more.

It's a breathtaking mistake on the part of a bunch of people, really.