The VW Golf pollutes as much as an 18-wheeler truck!

The New York Times has the answer to a question I have been asking myself since VW got caught cheating: why would VW owners bring their cars to be fixed, if the fix decreases the performances of their car? Here is the answer:

The E.P.A. cannot force owners to repair their vehicles, said Julia Ortiz, a spokeswoman for the agency. 

Automakers also cannot require owners to carry out the emissions recall, just as they cannot force owners to take vehicles in to complete a safety recall.
Some states require vehicles to pass emissions tests before they can be registered each year. But those tests are far less sophisticated than the E.P.A.’s, and the Volkswagens that are not repaired are sure to pass them, said John German, a senior fellow at the International Council on Clean Transportation, which played a crucial role in discovering the automaker’s deceit. 

That loophole means the air pollution consequences of Volkswagen’s action — at least on a small scale — are irreparable if enough owners refuse to have their vehicles fixed.

(...) 

Volkswagen must come up with an incentive plan to make repairing the engines irresistible, said Dan Becker, the director of the Safe Climate Campaign at the Center for Auto Safety. 

The article also explains how bad the polluting problem is:

Despite their small size, the Volkswagen diesels produce a large amount of nitrogen oxide pollutants, Mr. German said, up to 40 times what is allowed under the Clean Air Act. The Passat sedan is emitting an amount of nitrogen oxides similar to that of a modern, medium-duty truck, he said, while the Jetta — and its sibling the Golf — have emissions similar to those of a typical modern 18-wheeler, he said. The Jetta and Golf use a different emissions system than the Passat.