Volkswagen says it can fix its rigged engines in as little as 30 minutes but can't guarantee its solution won't affect the fuel consumption or the overall performance of the cars that were designed to cheat pollution tests.

It comes three months after the car maker admitted that it that used software to spew out as much as 40 times the legal limit for emissions, equating to more than 10,000 tonnes of nitrogen oxide pollutants each year.