Volkswagen is facing yet another legal battle in the diesel emissions scandal, as the US Federal Trade Commission (FTC) on Tuesday announced a lawsuit against the embattled German automaker for deceptive advertising, dpa reported. Between 2008 and 2015 VW sold more than 550,000 diesel vehicles in the US based upon false claims, according to the FTC's lawsuit. Over that seven-year span, VW had advertised its vehicles as "clean diesel," when in fact their emissions were dirtier than the law allowed, the FTC said. In September 2015, VW admitted that their diesel vehicles carried manipulative software to trick US emissions tests. In October, the FTC began investigating VW.