Volkswagen's cheating engines can't be easily fixed
The company has admitted that 11 million of its cars used illegal software to cheat emissions standards.
Now, many owners are demanding that the offending cars be fixed.
That's easier said than done, and Volkswagen has already tried - and failed - twice.
Here's the issue, according to the US Environmental Protection Agency: Cars with Volkswagen's 2-liter TDI turbo-diesel four-cylinder engines include software that detects when the car is undergoing emissions testing and turns on a suite of pollution-control systems.
But as soon as the test ends, the controls switch off, leaving the engine free to emit up to 40 times the legal limit of nitrogen oxide, a highly polluting gas. According to the California Air Resources Board, Volkswagen admitted to using a defeat device during a September 3 meeting with the agency and the EPA.
The problem for Volkswagen is that getting the engine's emissions in line with pollution standards probably means sacrificing something else.
"Building an engine involves balancing four factors - performance, emissions, durability, and fuel economy," explained Jake Fisher, Consumer Reports' director of automotive testing.
Right now, VW has sacrificed emissions to create a TDI engine that offers great performance, incredible fuel economy, and solid reliability.
"Whatever the fix is, it will likely sacrifice fuel economy and probably durability as well," Fisher said.
Two failed attempts
So fixing the cars won't be as simple as changing the software to turn on all of the vehicle's emissions-control systems.
"We aren't sure what the exact fix will be," Matt DeLorenzo, Kelley Blue Book's KBB.com managing editor, told Business Insider. "We also don't know what kind of performance or fuel economy the car will return when the emissions control is turned on."
Volkswagen actually tried to fix the problem using a software patch in December 2014 and then again in April 2015.
Neither attempt was successful.
Other options range from the recalibration of pollution-control systems to the installation of a Urea injection system that neutralizes NOx and particulates in the exhaust.
And even the installation of a Urea injection system - known commonly as AdBlue - can't guarantee the cars pass emissions. In a , the CARB noted that even 2015 model-year cars equipped with AdBlue failed the agency emissions tests in May.
The nuclear option
Buybacks are exceedingly rare in the automotive world because they call for the car company to spend millions if not billions to "buy back" defective cars from owners. Manufacturers typically avoid this route due to the exorbitant upfront costs and the negative publicity generated by the action.
According to KBB.com's DeLorenzo, there's a 50-50 chance a buyback happens in this case, and it all depends on the fix VW comes up with.
Class-action lawsuits
VW owners aren't standing idly by. They are taking action through the legal system in the form of class-action lawsuits.
"Volkswagen owners feel like they've been misled and deceived," Gibbs told Business Insider. "They thought they were getting a clean diesel and paid a premium for it."
Gibbs, founding partner of Girard Gibbs LLP, is one of the many lawyers representing owners of the 482,000 cars in the US affected by VW's emissions scheme.
In the suit, owners are demanding a buyback or a repair that would not compromise performance, emissions, and fuel economy.
However, the likely outcome here isn't going to be a buy back.