Court records cite Willis as saying his company has tuned more than 175,000 trucks—not all for delete purposes—which builds up his status as a figurehead for the diesel aftermarket.

Diesel is also a significant source of black ... Even a yearlong delay means more dirty trucks for years to come because ...

The legislature must ensure truck makers follow the rules to get rid of dirty diesel and deliver clean air by investing more ...

According to the map, the 10 ZIP codes with highest exposure are concentrated near the ports and along the 110, 710, and 605 ...