It seems that not having throttle plates on older diesel engines has it's risks. (mechanics.stackexchange.com)
Skeen explains that although new diesel vehicles are cleaner than ever before, some of the latest generation gasoline engines emit as much particulate matter as older diesel engines. (sciencedaily.com)
$ 40 million is available for DERA grant funding to implement clean diesel projects aimed at reducing emissions from the nation's existing fleet of old diesel engines. (epa.gov)