Volkswagen faces $15 billion payout in U.S.

Fifteen billion dollars - that's how much Volkswagen's U.S. settlement is going to cost them

The company admitted last year it had tricked regulators installing secret software in diesel cars that allowed them to emit pollution up to 40 times the legal limit

Now a source tells Reuters they'll be setting aside 10 billion dollars to buy back the affected cars and compensate the owners.

Experts following the settlement say VW had little negotiating power given the evidence.

Patrick Min, Senior Industry Insights Analyst for Truecar, says: "The settlement for Volkswagen is really the first step that they've made publicly after the admission of fault they made publicly in September of last year. So the amount of 15 billion dollars, far and away the largest amount in U.S. history is really the first step in terms of setting aside money in order to repair vehicles or actually buy them back from owners."

It will be the largest buyback offer in U.S. history affecting nearly half a million two litre diesel cars and the most expensive auto industry scandal ever.

Besides the buybacks, the settlement requires VW to spend about $5 billion dollars to offset emissions and boost zero emission cars.

A separate settlement with U.S. state attorneys general is expected to be over $500 million

Min adds: "I think it is going to be a blend, I think there will definitely be an option for owners to send their vehicle directly to Volkswagen. Also there will be an opportunity for Volkswagen to fix the vehicles that were affected and also partake in a cash settlement of some amount."

And VW faces a string of other costs from civil penalties to investor lawsuits and a criminal investigation plus a settlement over 85,000 larger polluting cars that's still months away.