Frank O'Donnell, executive director of the Washington-D.C.-based environmental advocacy group Clean Air Trust said Mack Trucks and five other companies have no excuses not to make cleaner engines.
"They can do it," O'Donnell said. "They signed a consent decree saying they would do it. We think (technology) is available to do it. But this industry has a history of evading standards, fighting against cleanup, fighting against standards. This is just more of the same."
The current dispute centers on claims by environmental groups and state officials that truck industry officials pressured the Environmental Protection Agency to allow the industry until 2007 to establish tough new procedures for testing truck emissions. The EPA this week agreed to change the date from 2004 to 2007.
Andrew Ryder, editor of Heavy Duty Trucking, an industry magazine, called the latest move "meaningless." That's because new trucks are cleaner trucks, he said.
"These engines are far, far cleaner than they were even five years ago," Ryder said. "The real news here is that the air is getting cleaner. Every time a new truck hits the road, the air is far, far cleaner." And because the new engineers are more fuel efficient, they are using less diesel, causing less pollution.
"Trucks as a whole today produce more pollution than 1970, when the Clean Air Act was passed, " he said. "There are more of them and they are driven more. They are a significant source of pollution."
All other major sources of pollution have decreased except big trucks, he said.
Mack and the other five companies, Cummins Engine Co., Detroit Diesel Corp., Navistar International Transportation Co., Caterpillar Inc., Renault and Volvo Truck Corp. signed the consent agreement in 1998. They make 95 percent of the big trucks in the country.