Lawsuit Alleges GM Cheated On Emissions Tests For 705,000 Trucks

May 2017 Duramax, Feature Trevor Mason

A class-action lawsuit was filed on Thursday that alleges that General Motors installed “defeat devices” on more than 705,000 Duramax-equipped Chevy Silverados and GMC Sierras. 

It’s hard to give a big corporation the benefit of the doubt, especially in the wake of last year’s so-called “Dieselgate” with Volkswagen. That particular scandal was the result of Volkswagen admitting it tampered with testing on about 550,000 vehicles, which is a smaller number than the allegations against GM. For their part, GM refutes the lawsuit as having no merit. In a statement, they said, “These claims are baseless and we will vigorously defend ourselves. The Duramax Diesel Chevrolet Silverado and GMC Sierra comply with all U.S. EPA and CARB emissions regulations.” 

Now defeat devices aren’t necessarily illegal in and of themselves, insofar as they’re used properly and for specific reasons. The issue, according to the suit, is that testing showed that the trucks emitted two to five times the limit allowed by law. 

Some choice words from the lawsuit right here: “Increased sales and thus increased profits drove GM to use at least these three defeat devices in its Duramax diesel engines. By reversing the traditional order of the exhaust treatment components and putting the Selective Catalytic Reduction (‘SCR’) in front of the Diesel Particulate Filter (‘DPF’), GM could obtain and market higher power and efficiency from its engines while still passing the cold-start emissions certification tests. This made GM’s trucks more appealing and competitive in the marketplace, driving up sales and profits.” 


This could be disastrous for GM if it turns out to be true. Just look at what’s left of Volkswagen’s reputation if you need further proof. Another curious wrinkle to the case is that German auto supplier Bosch—who was part of Volkswagen’s troubles for allegedly helping their defeat device—is also named as a defendant in the suit. 

If you’re so inclined, you can read the entire 191-page document here.

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