SAN DIEGO -- Even General Motors executives acknowledge that the current Chevrolet Impala's long-in-the-tooth design and platform make it appealing mostly to fleet buyers. Soon it will fill that role exclusively.

GM says it will sell the current Impala, which has been on sale for eight years, for about one more year to fleet customers only as a 2014 model. The soon-to-be launched replacement will be geared for retail buyers and will hit showrooms by mid-April.

The fleet-only model will be called the 2014 Impala Limited. It likely will be produced until spring 2014, Chevrolet marketing chief Chris Perry said here during a media launch of the redesigned sedan.

Extending the life of the older Impala is a way for GM to capitalize on the popularity of the no-frills sedan among car-rental companies and fleet buyers who want an inexpensive big car with decent fuel economy. It also will allow Chevrolet to re-position the new Impala as a stylish and higher-priced Chevy flagship sedan.

"The Impala has become more of a fleet car over the last several years, and this allows us to continue to meet that demand for our fleet customers," Perry said.

Last year nearly 75 percent of the 169,351 Impalas that Chevy sold were to fleet buyers. For the forthcoming redesigned car, Perry said he expects retail to account for around 70 percent of sales.

GM will launch advertising for the 2014 Impala in early April with commercials during the men's college basketball Final Four and the first week of Major League Baseball, Perry said.

Chevrolet showed a glimpse of its Impala creative work last month, when it featured the sedan in a two-minute anthem-style commercial that included four other Chevy nameplates. The stand-alone Impala spots will include the same black-and-white motif set to Frank Sinatra's "Fly Me to the Moon," featuring a tuxedo-clad man pulling up to the entrance of a country club.

Perry said the commercials, which he described as "Mad Men-esque" after the AMC network TV series about a fictional 1960s advertising agency, are intended to play on the 55-year-old nameplate's rich heritage while also showcasing its "head-turning" design.

The spots were created by Commonwealth, the Detroit cooperative agency formed last year between Interpublic Group's McCann Worldgroup and Omnicom Group Inc.'s Goodby, Silverstein & Partners.

"Styling is a big reason for purchase in this segment, and we feel that the Impala is well positioned in that regard," Perry told Automotive News .

As part of the baseball tie-in, Impalas also will be on display at major league baseball parks.