Volkswagen said it will outfit 7 million vehicles annually with a filter that will reduce soot emissions by 90 percent by 2022, but environmentalists are skeptical the company will live up to its goals.

"The filters will cause a significant reduction in the vehicles' soot emissions," said Ulrich Eichorn, head of group research and development for the German automaker.

"Following increases in efficiency and lower [carbon dioxide] output, we are now bringing about a sustained reduction in the emission levels of our modern petrol engines by fitting particulate filters as standard," he said in a company statement.

The German automaker announced it will start installing new particulate filters for gas-powered vehicles in 2017. The process will start in June with the 1.4-liter TSI engine in the Volkswagen Tiguan and the 2.0-liter TFSI engine in the Audi A5.

But it seems the company's Dieselgate scandal has caused environmental groups to be skeptical about Volkswagen's desire to live up to its lofty promises.

Volkswagen ran a scheme to install software that could tell when its "clean diesel" vehicles were undergoing emissions tests. During testing, the vehicles would reduce the amount of nitrogen oxide released, but when the software recognize the cars were being driven normally they would spew up to 40 times the legal amount of nitrogen oxide into the atmosphere.

Executives at the highest levels of the company knew about the scheme and the company's lawyers instructed engineers to destroy evidence, according to allegations from New York's attorney general.

The company has settled with the Environmental Protection Agency and California regulators for $14.2 billion, the largest settlement for an environmental crime in history. The EPA declined comment on the new filter.

The scandal leads Andrew Linhardt, an associate Washington representative for the Sierra Club, to question whether VW can be trusted to reduce particulate matter emissions.

"They blatantly broke the public's trust, so I'm a little skeptical of any their plans for reducing emissions and pollution," he said.

Linhardt said he's open to seeing what happens with the new filter and VW's pledges to be more environmentally friendly. He said the German automaker could go much further toward rebuilding its environmental reputation by becoming more involved with electric vehicle technology.

"It would show they're serious about reducing emissions," he said. "This new particulate filter sounds good in theory … but we know the emissions from an electric vehicle are zero.

"That would go a long way toward making sure they're serious for making up for their past actions," he added.