A preliminary settlement for Volkswagen and Audi TDI diesel cars with 2.0-liter 4-cylinder engines is awaiting approval by a federal judge.
But the Volkswagen Group and U.S. regulators have not made as much progress in addressing affected VW, Audi, and Porsche TDI models with 3.0-liter V-6 diesel engines.
Audi's sales boss now believes an agreement could be reached relatively soon, though.
A "final agreement" should be reached by October, or early November at the latest, Dietmar Voggenreiter told Reuters in an interview published late last month.
At roughly 85,000, the number of affected V-6 diesel cars in the U.S. is much lower than the 4-cylinder group, which includes about 450,000 cars.
Vehicles equipped with the 3.0-liter diesel V-6 include five different Audi models—A6, A8, and A8L TDI sedans; the A7 TDI hatchback; and the Q5 and Q7 TDI sport utility vehicles—along with the Porsche Cayenne Diesel and the Volkswagen Touareg TDI.
2013 Audi A7 TDI
Last month, U.S. District Court Judge Charles Breyer called for VW and U.S. regulators to make at least some progress on a settlement for the V-6 TDI models. He also oversees the case on the 2.0-liter diesels.
Breyerset a November 3 hearing date for an update on the V-6 settlement.
That declaration did not include a mandate for a final settlement, so Voggenreiter's prediction that a final settlement will be reached by roughly that date may be somewhat optimistic.
The California Air Resources Board (CARB) has already rejected one plan for modifications to the V-6 TDI models, submitted in February.
2013 Audi Q7 TDI S Line
Both CARB and the U.S. Environmental Protection Agency (EPA) must approve any emissions-related modifications to the affected diesel vehicles.
The two agencies haven't approved modifications for the 4-cylinder TDI models either, meaning owners will likely have to continue waiting even after the settlement for those cars receives final approval.
The approval for the 4-cylinder settlement can only come on or after an October 18 hearing.
Any settlement for the V-6 models would likely include a buyback provision, as well as the option of possible modifications, similarly subject to approval by Federal and state regulators.