An attorney for Volkswagen on Thursday told a US judge that the carmaker thinks it can fix larger diesel vehicles involved in a costly emissions-cheating scandal.

Bringing its VW, Porsche, and Audi vehicles with 3-liter engines in line with air quality promises could spare the automaker from having to buy them back.

"The company believes it can fix the 3-liter to the standard to which those cars were originally certified," Volkswagen attorney Robert Giuffra said during a status hearing in San Francisco federal court.

"We believe that the fix will not be a complicated fix, and we believe it will be one that will not have an adverse impact on performance."

Giuffra told US District Court Judge Charles Breyer that the process will take time due to testing to make sure the fix is lasting.

Breyer set a July 26 hearing to discuss potential approval of a multi-billion-dollar settlement regarding 2-liter engine vehicles.

"It is the responsibility of the court to determine whether this proposed settlement is fair, whether it's reasonable," Breyer said.

In a settlement filed in federal court on Tuesday VW agreed to a record $14.7 billion payout in the United States, pledging to buy back or fix 2-liter engine vehicles that tricked pollution tests, and pay each owner up to $10,000.

It announced a separate deal to pay $603 million to settle consumer protection claims from US states.

US authorities broke the scandal when they exposed how VW had installed software into some of its diesel engines, enabling the vehicles to spew up to 40 times the permitted amounts of nitrogen oxides.

Volkswagen subsequently admitted that it had installed the suspect software into as many as 11 million vehicles worldwide.

Elsewhere around the world, VW is facing a number of regulatory probes and lawsuits filed by car owners who feel they have been duped and investors who are seeking compensation for the massive drop in the value of their shares.

"Volkswagen as a company is very committed to regain the trust of its customers, its regulators, and the American public, and we want to make things right," Giuffra said during the brief court hearing in San Francisco.

"I think the settlement agreement is an important first step."