The U.S. new-car market is on the cusp of a consumer-preference shift to the compact segment, General Motors’ top sales analysts predicts.

“There’s definitely going to be a time when the (Chevrolet) Cruzes of the world are the top-selling cars in this market,” Don Johnson says. “It could well happen in 2012.”

Such a move would end midsize-segment dominance that has spanned four decades, according to Ward’s data.

The Cruze was the best-selling car in the U.S. in June, but that was not the case in July. Longtime consumer favorite, the midsize Toyota Camry, recorded 27,016 deliveries.

Climbing fuel prices are compelling consumers to consider a change in their buying habits, Johnson tells journalists during a conference call outlining GM’s July sales performance.

The auto maker tallied 214,915 light-vehicle deliveries for an 11.8% jump, compared with like-2010, according to Ward’s data.

The C-segment Cruze accounted for 24,648 sales – second in the GM portfolio to the Chevrolet Silverado fullsize pickup, the auto maker’s volume flagship and a perennial sales leader in the total U.S. light-vehicle market.

With the average national per-gallon price of regular-grade gasoline trending nearly $1 higher than year-ago at $3.70, according to the American Automobile Assn., consumers are seeking relief by downsizing, Johnson says.

But because of packaging and powertrain innovations that strategy portends less compromise and more benefits than in years past, he adds.

The Cruze features 110 cu.-ft. (3.1 cu.-m) of interior volume, compared with its predecessor, the Chevrolet Cobalt, which offered 99.9 cu.-ft. (2.8 cu.-m).

The Cruze also boasts a highway fuel-economy rating of 42 mpg (5.6 L/100 km), compared with 37 mpg (6.4 L/100 km) for the defunct Cobalt.

Upper Small Cars last dominated the U.S. car market in the 1980s, according to Ward’s segmentation. Five times during that decade a compact model topped the list of the nation’s best-sellers, with the Ford Escort achieving the feat last in 1988.

While GM’s July mix favored light trucks over cars, 134,840 deliveries to 80,075, the auto maker’s car sales outgained its light-truck tally 12.3% to 11.5%, according to Ward’s data.

Inventory shortages of the hot-selling Chevrolet Equinox cross/utility vehicle and its GMC Terrain platform-mate created “downward pressure” on their sales, Johnson concedes. But Equinox deliveries still soared 79.9% while Terrain sales doubled.

Cadillac was the only GM brand that did not achieve positive results in July. Its car sales plunged 21.3%, while its light trucks slid to 23.8%.

“Luxury seems to be soft,” says Kurt McNeil, vice president-Cadillac sales.

Through July, GM’s sales were tracking 15.7% ahead of like-2010 on 1,476,526 deliveries, according to Ward’s data, which is adjusted for selling days. There were 26 last month, compared with prior-year’s 27.

Johnson says GM noticed a drop in consumer confidence related to the U.S. debt-crisis debate. “We’re very happy to see the bipartisan solution reached,” he adds.