Despite handling the Chevrolet Volt fire-risk issue brightly going to great lengths to dispel current owners’ fears and satisfy them, media headlines seem to have taken their toll on the extended range EV’s sales after all.

According to CNW Marketing president Art Spinella, a new survey conducted by his research company reveals “a decline in the consideration of the GM vehicle”.

The study shows that the number of early adopters “Likely” or “Very Likely” to buy a Volt between July and December decreased by 20.5% after the fire reports, a percentage that was double among the general public. Electric vehicle enthusiasts are the only ones not affected by the reports, yet analysts expect the Volt to will miss its 2011 sales target by around 20%.

NHTSA has instigated a federal investigation on the issue of lithium-ion batteries after a crash-tested Volt’s batteries caught fire last May, and on subsequent crash tests, there was a case of sparks and smoke.

General Motors stated that there is a certain protocol concerning the handling of the battery pack after an accident, which, in the first case, was not followed. Nevertheless, the Detroit maker continues to cooperates with federal agencies in the investigation, and has already changed the battery handling protocol and may even make modifications to the battery pack.

Meanwhile, the Associated Press reports that a person familiar with the investigation revealed that the most likely cause of fires was not the battery pack itself, but leaking coolant.

The unnamed source told AP that the coolant did not catch fire immediately, but slowly crystalized, thus creating a short circuit that caused the delayed fires.

As GM notes, none of the 5,500 Volts sold so far have caught fire. Nevertheless, the House of Representatives has scheduled a hearing next month to look both into the Volt safety as well as the way the Obama Administration has handled the NHTSA investigation.

The U.S. Department of Transportation Secretary, Ray LaHood, told Congress “I believe the Volt is safe to drive”. On the other hand, Jim Jordan, the Ohio House member in charge of the committee, responded that “it gives us great concern that recent reports indicate important safety information may have been omitted in testimony before a committee just a few weeks ago.”

LaHood responded that, despite claims by Republican House Members that the Administration may have held back since it has a stake in GM; the DoT is “not in the business of protecting the auto industry. We’re in the business of making sure cars are safe.”

Story References: Detroit Bureau & BuisnessWeek