Volkswagen says its manipulations of carbon dioxide emission levels affect more gasoline-powered engines at the German automaker than it had previously disclosed.

VW said on Nov. 3 it had understated the level of CO2 emissions in around 800,000 predominantly diesel-powered vehicles, with some models using a 1.4-litre gasoline engine.

A spokesman said on Monday that more gasoline engines were implicated by the CO2 violations, adding to a statement the carmaker had released after business hours on Friday.

Carbon dioxide is a greenhouse gas that causes climate change and regulators set limits on how much can be emitted by automobiles.

About 24 gasoline-powered models were listed, among them vehicles such as the 1.0 litre Seat Ibiza, the 1.2 litre VW Jetta and the 2.0 litre VW Passat.

Volkswagen said it was notifying regulators around the world about the issue and consumers could check into the status of their vehicles on its websites.

All the cars are currently being retested in Germany, it said.

A VW spokesman confirmed on Monday more gasoline engines were implicated by the CO2 malfeasance than previously disclosed. The previous revelations about cheating on emissions involved its diesel engines.

The revelations about fuel economy and CO2 emissions have deepened the crisis at Volkswagen, which is facing a crisis of consumer confidence, as well as an expensive recall of its vehicles.

The revelation comes after VW's admission in September that it rigged emissions tests for four-cylinder diesel engines on 11 million cars worldwide, including almost 500,000 in the U.S. It has already set aside €6.7 billion ($9.5 billion Cdn) to cover the costs of recalling those vehicles, and these additional problems are projected to cost $2.8 billion.