It's the first time since Consumer Reports began awarding cars and light trucks numerical scores in 1992 that a domestic car is the top-scoring sedan.
"The domestic automakers, they do a lot right but there's often something that's holding them back," Jake Fisher, director of Consumer Reports' automotive testing, told Automotive News. "This car just kind of gets it all right. They really have a winner here."
A Japanese model has held the top-scoring sedan spot 12 times and a European model has had it on nine occasions, according to the magazine.
In its September issue, which goes on sale Aug. 1, Consumer Reports says the Impala "rides like a luxury sedan, with a cushy and controlled demeanor," and "is competitive with cars that cost $20,000 more, including the Audi A6 and Lexus LS 460 L," along with the Acura RLX and Jaguar XF.
It praises the car's "solid, almost vaultlike atmosphere" and the Chevrolet MyLink control system while dinging the car for limited rear visibility and fuel economy that isn't quite best in its class.
"It has been transformed from a woefully uncompetitive and outdated model that was to be avoided even as a free upgrade at the rental-car counter into a thoroughly modern and remarkably enjoyable vehicle," the magazine said.
The 2014 Impala has also been widely praised by other publications, including The Wall Street Journal, Car and Driver, and Autoweek.
On a conference call with analysts today to discuss GM's second-quarter financial results, CEO Dan Akerson said the company has product momentum, citing the Impala rating from Consumer Reports and GM's strong showing in recent J.D. Power and Associates rankings of initial quality and new-vehicle appeal.
"Results like these are changing perceptions about our brands for the better," Akerson said.