Yesterday, Volkswagen CEO Matthias Mueller said that owners of affected diesel vehicles will need to have them 'refitted'. Muller didn't go into detail about what he meant, but Reuters has some possible ideas.
Speaking with experts, Reuters says Volkswagen might have to develop different solutions for the 482,000 vehicles affected in the U.S. This comes down to Volkswagen using two different systems for controlling emissions; lean NOx traps (most Volkswagen diesel vehicles involved in the scandal) and a urea injection system (Volkswagen Passat TDI).
For vehicles equipped with the lean NOx traps, Volkswagen could get away with using a software update says Marc Trahan, former executive vice president of group quality for Volkswagen. Trahan says the older engines shouldn't need to have newer hardware installed as it would require extensive "re-engineering" and cost a large amount of money. Others argue that a hardware solution may be the only way these vehicles meet EPA standards.
For the Passat TDI, that might only need a software update. But it might bring up another problem; more fill-ups for the urea injection system.
Most experts do agree these updates will cause the loss of performance and fuel economy.