How does it report? And to whom?
“My VW TDI has a dye pack in the fuel line and a color sensor. It will report if I used untaxed fuel.
How does it report? And to whom? “
I mentioned to the VW salesman that I had purchased a 500 gallon diesel tank from a horse rancher. He said, “Oh, no. You need to clean it very carefully. There can’t be a drop of untaxed fuel in your car. (Then he explained the color sensor and the dye pack.) Fuel that is off-road (untaxed) is dyed a different color than fuel you buy that is taxed. The salesman was apologetic when he explained the dealership (whatever one I went to) would see the color sensor code and report it for fear this was a government test. (To see if they were reporting.)
In Europe, where diesels are much more popular, there are agents who literally sniff your exhaust to make sure you’re not burning French-fry oil. (Which would be untaxed.) It used to be that restaurants had grease barrels that somebody collected. Now those barrels are under guard as people steal them to fuel their cars. (A diesel will burn most anything you could call oil.)