Porsche is dragged deeper into Dieselgete

Volkswagen has taken quite a beating since news of its diesel defeat devices began making headlines nearly 15 months ago. Though the company has been making progress on repairing its vehicles and its brand, it's not out of the woods yet.

New reports suggest that Volkswagen has been using emissions-test-cheating software on gas-powered models, too--specifically, those made by Porsche.

Diesel damage to date

Volkswagen's eponymous, mass-market VW brand has been hit hardest by Dieselgate, with month after month of sliding sales stats. In fact, the damage to VW has been so bad, the brand may ditch diesels altogether--at least in the U.S.

Audi has felt far less pain. In fact, VW's luxury sibling has fared exceedingly well on sales floors since the crisis began. That could change, though, as investigations of the company determine whether Audi engineers designed defeat devices for diesels way back in 1999. And of course, more recent headlines suggest that Audi's gas models could be illegally rigged, too.

Like Audi, Porsche, has remained relatively unscathed by Dieselgate. True, it had to suspend diesel sales, but thanks to a growing economy and low fuel prices, consumers have been eager to purchase the brand's gas-powered cars and crossovers. As of November 30, Porsche's U.S. sales were up a respectable 5.1 percent over 2015.

More trouble ahead

The company's blue-sky days could be coming to an end, though. A tipster close to Porsche recently told Germany's Transport Ministry and Federal Motor Transport Authority that the company had equipped some of its gas models with defeat devices. Those devices are allegedly capable of determining when a vehicle is undergoing an emissions test and reducing carbon-dioxide emissions accordingly.

Interestingly, reports indicate that the software works by tracking the movement of a car's steering wheel. If there's no movement of the wheel after a certain time, the software determines that the vehicle is being tested and dials down CO2 emissions. 

Why is that interesting? Because it sounds suspiciously similar to the emissions software discovered on Audi models by the California Air Resources Board--software that may have been installed on vehicles as recently as May 2016. 

In response to the allegations, Porsche has denied any wrongdoing. While the company admits that there is software designed to track the movement of its steering wheels, Porsche says that the software is designed to improve performance and has no effect on emissions. 

Note: for purposes of clarity, "Volkswagen" has been used to refer to the Volkswagen Group parent company, while "VW" has been used to refer to the company's mass-market brand of automobiles.