Volkswagen said in its recall statement that "extensive research has confirmed that replacing synthetic oil with mineral oil will eliminate the possibility that this issue could occur. Therefore, Volkswagen has decided to replace synthetic oil with mineral oil in affected vehicles as a preventative countermeasure at zero cost to the customers in China and other affected markets".

The General Administration of Quality Supervision, Inspection and Quarantine said that as of Dec 26, the authority has helped carmakers announce 130 batches of vehicle recalls involving 3.76 million vehicles in China, 17.37 percent more than last year.

Chen Xitong, spokesman for the country's quality watchdog, said that of the total amount, 52.17 percent of the recalled vehicles, or the equivalent of 1.96 million vehicles, were recalled after investigations by the administration and that 3.28 million vehicles were voluntarily recalled by domestic automakers.

The administration issued a new rule, effective as of Oct 1, that gives responsibility to the seller for repairs, replacements and refunds pertaining to private cars manufactured and sold in China.

"The big increase in recall batches and numbers this year can be attributed to the implementation of the new policy, which effectively regulates the recall sector," said Cui Dongshu, deputy secretary-general of the China Passenger Car Association.

Jia Xinguang, an independent auto analyst based in Beijing, added: "The number of recalled vehicles has no direct relationship with the quality. The increased numbers of recalls indicate that more manufacturers are shouldering their liability to customers. Chinese customers should treat recalls rationally."