McDonald's betting commuters will gobble up salad in a cup.

McDonald's newest entree in Southern California comes in a 21-ounce plastic container and easily fits into most car cupholders.

You can pick it up during your morning commute and it will stay fresh most of the day - until you dump on the dressing and shake it up.

It's called the Salad McShaker - an entree tailor-made to appease L.A.'s army of calorie-counting commuters.

"This creates a new twist, a new look and provides a fun approach to salads," said Mike Mangione, president of the McDonald's Owner Operators Association of Southern California. "Considering 50 to 60 percent of our business comes from our drive-thru, we can better tap into that segment with this handy salad. Before, you had to be a real salad person to order a salad through the McDonald's drive-thru."

The new addition will be in 550 restaurants in Los Angeles, Orange, Riverside, San Bernardino and Ventura counties by the week of May 17. The launch follows test runs in places like Salt Lake City, Columbus, Ohio and Raleigh-Durham, N.C.

The salads are another attempt by the Oak Brook, Ill.-based burger chain to reinvigorate sales. Just last week, McDonald's announced its acquisition of Columbus, Ohio-based Donatos Pizza Inc.

"The old and new McDonald's aren't the same. The fact that consumers are exposed to new varieties of food only reinforces the fact that McDonald's needs new menu offerings to bring customers back for different day breaks," said Ron Paul, president of Technomic Inc., a restaurant consulting firm in Chicago.

With the upscaling of fast food and the entrance of more health-oriented players like Koo Koo Roo, La Salsa and Rubio's, analysts have criticized McDonald's for being slow to innovate. Past product launches have had a dismal track record, with flops like the Arch Deluxe and McLean Deluxe hamburgers, as well as pasta and pizza at some locations.

Until the recent success of the McFlurry, an ice cream concoction mixed with candy and cookies, the last successful offering was Chicken McNuggets in 1983.

But some analysts question whether customers will ever come to associate lean cuisine with the Golden Arches.

"People want low-price foods that they can quickly fill up on from McDonald's. It's hard to change that concept," said Phyllis Marshall, owner of consulting firm FoodPower in Costa Mesa.

But Mangione, who owns eight franchises in Los Angeles, Torrance and Long Beach, says the salads provide an attractive low-calorie alternative.

"Maybe we have built our bread and butter on the hamburger business, but there's a market out there that we haven't put enough attention to in the past," he said.

The salads come in three varieties: the garden salad, the grilled chicken Caesar, and the chef salad. Dressing will include a fat-free herb vinaigrette and reduced-calorie French. McShakers will replace the current garden and chicken salads that have been served by McDonald's since the early '80s but failed to become big sellers.

To aid sales, the Salad McShaker will be offered all day so people stopping in the morning can pick one up to have later for lunch or dinner.