Chevrolet Impala prototype testing with CNG powertrain - rear view

When it comes to fleet vehicles, the Chevrolet Impala definitely plays an important role for General Motors, and it looks like GM is hard at work developing the next-gen Impala for bulk-buying businesses. The Motoring Journal recently spotted a handful of Impalas testing in Colorado with minor camouflage, but upon closer inspection, these appear to be test mules for a new compressed natural gas (CNG) model – a powertrain combination far more likely to find favor with fleet buyers than everyday consumers.

Aside from the obvious "CNG" stickers affixed to the decklid, these cars also have different exhaust outlets than what we saw on the V6-equipped Impalas during our first drive of the sedan back in March. Images also show under the hood with a different engine cover and plenty of exposed wiring as the CNG system continues testing. There was also an electrical connector poking out of the front fascia, and at least one of the sedans had a receiver-style trailer hitch.

During the launch of the 2014 Impala, Chevrolet said that it is looking to flip the current fleet-to-retail from 70:30 to a more profitable and resale-friendly 30:70 ratio, and this new CNG Impala could be a good way to retain some of that 30-percent fleet business. We reached out to GM for word on when a CNG Impala might arrive, and received this response:

We do offer a CNG van and a bi-fuel pickup truck, but still studying the demand for CNG powered passenger cars. Infrastructure is a consideration for anyone buying these types of vehicles. Unfortunately, there's nothing to announce today on this front.

Our best guess is that it could debut for the 2015 model year, since the ninth-generation model is carrying over for fleet-only sales as the 2014 Impala Limited.