Pickup Owners Launch Class Action Emissions Lawsuit Against General Motors

General Motors is facing a consumer lawsuit from a group of its US customers who have launched a class action, claiming that as many as 705,000 Chevrolet Silverado and GMC Sierra trucks fitted with Duramax diesel engines have cheated emissions tests.

The suit alleges that GM has installed three separate emissions defeat devices, but the text we’ve seen so far doesn’t define exactly what type these devices are. The complaint reads like this:

“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 in front of the diesel particulate filter, GM could obtain and market higher power and efficiency from its engines while still passing the cold-start emissions certification tests.”

We’re not sure exactly what legal grounds are being used, here, and at this stage we have no idea whether any rules have actually been broken. The allegations don’t seem to go into specific detail about any supposed discrepancy between official and real-world emissions, for example.

But GM has hit back with a short two-sentence statement, released on its own with no further information.

“These claims are baseless and we will vigorously defend ourselves. The Duramax diesel Chevrolet Silverado and GMC Sierra comply fully with all US EPA and CARB emissions regulations.”

You get the feeling they’re not happy. We’ll keep you posted on any developments this throws up.