According to media reports, officials from the California Air Resources Board recently discovered that software in certain Audi models alters the shift pattern of the transmission during emission testing to improve the test result while reverting to different patterns in ordinary driving.

Apparently the transmission is programed to shift gear earlier while on a dyno, or rolling road, for testing, and only reverts to real-world behaviour when the steering is turned through 15 degrees.

This has led to a new round of class actions; this time for Audi.

According to documents filed on November 10 in Minnesota as part of a class action in the United States District Court, the Audi models involved include the A6, A8, Q5 and Q7 fitted with 3.0-litre petrol engines and automatic transmissions.

Audi Q5

The latest accusations involve emissions of carbon dioxide, held to be a major contributor to global warming. Regulators in both Europe and the United States have instituted stricter standards for carbon dioxide emissions in recent years.

German publication Bild am Sonntag reports that the US Environmental Protection Agency had commenced investigating Audi over the most recent software revelations, and was asking questions to try and determine whether the systems constitute a defeat device in petrol-powered cars.

A VW AG company spokesperson said last weekend that “dynamic shift programs can lead to incorrect readings and results that cannot be reproduced”.

Audi apparently believes that the shifting program does not violate any European laws, but the situation in the US is less clear and needs to be determined by US authorities.

The allegations in the US class action are far less equivocal.

According to documents lodged with the US District Court: “These defeat devices are designed to surreptitiously limit emissions and increase fuel efficiency when the vehicles are being subject to regulatory emissions and fuel-efficiency testing.

The calibration of Audi’s transmission is at the centre of the most recent emissions scandal allegations

“The defeat device is a sleight of hand software program designed by Volkswagen’s engineers that directs the engine to run in low power ‘clean’ mode during emissions testing, so as to be compliant.”

The existence of this particular software does not appear to be contested, but there are certainly different views as to its legality and the intent of those who designed it.

The Wall Street Journal has reported that use of this software was discussed in early-2013 during a test drive of new cars in South Africa by senior VW management.

Minutes of a meeting there reportedly show the head of Audi’s powertrain division saying: “The shifting program need to be configured so that it runs 100 per cent on the treadmill but only 0.01 per cent with the customer”.

A report in The Australian earlier this week said that, “Audi disabled the test recognition shortly before Volkswagen admitted to cheating on diesel emissions in 2015”.

European regulators are said to have been caught out by these US revelations, with the German transport minister ordering his officials to urgently contact US authorities for information before making their own assessment of the situation.

Audi Australia was contacted for comment but a spokesperson said it would be inappropriate for the company to comment on situations in the US and Europe.

By Daniel Cotterill

Audi A6