A Detroit car came within a whisker of outselling Honda’s Accord last month. In fact, if you count those sales a certain way, the car did outsell the Accord, and it trails only Toyota’s Camry in the race for the best seller in America.

I am talking about the Chevrolet Impala, a big husky sedan that General Motors (nyse: GM - news - people ) builds in Ontario, Canada, but we still consider it a Detroit car. If nothing else, the Impala shows that the home team can compete.

Almost unnoticed, GM’s Impala has been a strong and steady performer. It has been on the “Recommended” list of Consumer Reports magazine. Impala is an old Chevy name, taken after the African antelope, as you probably guessed from the familiar emblem. Years ago, GM dropped the name in one of Detroit’s silly name-killing sprees, and then revived it on a 2000 model. Note that now Ford Motor (nyse: F - news - people ) is bringing back the Taurus name.

Despite all its success, the Impala seem less than beloved by GM executives. This car does not fit their ideas of what makes for a winner today.

Best-Selling Sedans in the U.S January 2007 January 2006

Toyota Camry 31,461 27,440
Honda Accord 25,714 27,440
Chevy Impala 25,275 21,648
Nissan Altima 24,394 16,758

Now here is the trick. The Impala comes only as a four-door sedan; no coupe, no convertible and no crossover. But Chevy sells a two-door coupe called the Monte Carlo, which is nothing but a two-door Impala with a fancy name. If you throw in Monte Carlo sales, then the January Impala total is 26,814, which puts it ahead of Accord and second to Camry. OK, unlike the Japanese, GM sells more of those cars to fleet buyers, but the Impala is still a sales success.

January was no fluke. Look at all last year’s numbers:

Sedan Sales 2006
Toyota Camry 448,445
Honda Accord 354,441
Chevy Impala 289,868
Nissan Altima 232,457
Ford Taurus 174,803

Again, if you toss in those Monte Carlo coupes, then the Impala total is 323,981. Sales of the Honda Accord are likely to slow in 2007 (it is the last year for the present model), so I think that the Impala will be on its tail all year.

Those Monte Carlo coupe numbers used to run 65,000 to 70,000 a year. For the last two years, they have fallen to 35,000; the January rate was half that again. Some attribute this to the decline in the coupe business. Others say the Impala, which GM dolled up for 2006, became more attractive and is winning coupe buyers. Others say that Chevy has been pumping its marketing money into other vehicles--the new Silverado pickup, the HHR little wagon and the sport utility vehicles--and short-changing the Monte Carlo. That is what I believe.

That Impala is big, but not pricey. It weighs a few hundred pounds more than the Camry and Accord, carries a V-6 or a V-8 engine; the V-8 accounts for about 10% of the sales. All its rivals carry four- and optional six-cylinder engines, and most of the sales are with the smaller four motors. A typical Impala price is $22,000, and that is for a V-6. The Japanese get that much for a car with a four-cylinder engine. This makes the Impala something of a bargain.

Now if you are a big American, 6’1” and 250 pounds, the Impala is great. Here is the rub: If you are a GM executive, you have a problem with it. That is because the Impala is not “global.” It is an American car, designed for Americans. It was not designed in Germany for snooty Europeans. GM does not sell it abroad. Today, GM kowtows to the idea of global cars, designed for production and sales around the world.

The Impala is not the chosen model to take on the Camrys and Accords, no matter how well it sells. Instead, GM favors a model, the Malibu, which is a step down in size from the Impala, even though GM sold only 164,000 last year, about half the Impala/Monte Carlo numbers. The difference is that they build Malibu on a global architecture.

GM thinking goes like this: The volume sellers in this family car market are the four-cylinder Toyota Camrys and Honda Accords. Impala is too big to put a four-cylinder in it. Instead, we will push the smaller Chevy Malibu as the volume car. We will give the 2008 (coming late this year) Malibu a new sweet looking exterior and better interior. The company will even put its new six-speed automatic transmissions on the high-end four-cylinder Malibus.

GM figures on pushing the Impala upscale to the richer part of the market. They even think of making it rear-drive again one day. One rumor is that the company will turn toward its Australian affiliate for the next Impala, just as it apparently plans to do with a new big Pontiac sedan, the G8. They see the Impala becoming sort of an Avalon, which is an upscale Toyota Camry. The aim is to push Malibu sales up and let Impala prices climb and sales fall.

Well, it is a plan. That new Malibu’s sales surely will increase next year. Yet, I say that to compete with the Japanese it is better to be different than to copy them. Maybe Americans really like bigger cars, and would prefer six-cylinder cars to four-cylinder cars--if the prices were close. If Chevy had a line of Impalas, with a newer platform, the car could give the Japanese an even better run for first place.

Impala proves that Detroit can still build a car that appeals to what Americans prefer. Too bad that General Motors does not recognize that it has a winner