On Thursday, Volkswagen Group of America CEO Michael Horn testified before the House Energy and Commerce Committee.

Horn identified some of the possible fixes owners of the half million cars affected by the emissions scandal in the US could expect.

The executive outlined repairs that will involve 5-10 hours per car for most vehicles.

The majority of thew affected cars won’t be able to be brought up to an acceptable emissions standard with a software fix. Rather, they will require a replacement emission-system technology.

This is less expensive for VW than buying back vehicles, but it’s still far costlier than a simple software upgrade.

According to Horn, the affected 2.0-litre TDI engines sold in the US from 2008 to 2015 are broken down into three separate generation groups.

Gen 1: Affects roughly 430,000 vehicles which tend to be older model year cars.

According to Horn, the cars in this group will likely require more than just a software update.

“We are working on both hardware and software solutions,” Horn said to the Committee. Possible hardware fixes could include a Urea SCR tank that neutralizes harmful exhaust particles and a specific catalytic converter for nitrogen oxide (NOx).

This group will require the most work to fix. VW doesn’t yet have a target date for when this repair will be available.

Gen 2: Affects roughly 90,000 2012-2015 Passat sedans. According to Horn, this group of the cars will likely require only a software fix, likely be available middle of 2016.

Gen 3: Affects roughly 70,000 vehicles and could require only a software fix, but he wasn’t able to get into much detail before a congressman cut him off. Horn did say that that the fix for the Gen 3 cars could be available as early as the beginning of 2016.

Horn noted that the proposed fixes will likely affect the performance of the cars. Fuel economy of the affected cars will match up with the EPA estimates posted on sales window stickers, but the cars will see a slight decrease in top speed.

The recall affects 482,000 diesel-powered cars sold in the US since 2008. They include:

• Volkswagen Jetta TDI: 2009-20015
• Volkswagen Beetle TDI: 2009-2015
• Audi A3 TDI: 2009-2015
• Volkswagen Golf TDI: 2009-2015
• Volkswagen Passat TDI: 2012-2015

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