U.S. consumers bought more cars in September than in the previous year, but early sales results from leading automakers on Wednesday were mixed.
General Motors, Fiat's Chrysler Group and Nissan Motor all reported year-to-year sales gains, but Ford Motor said sales fell slightly from a year ago. Toyota sales actually decreased, contrary to an expected gain.
Read MoreToyota recalls pickups to fix fire hazard
The generally positive results indicated industry strength continued as summer waned. A Reuters survey of nine analysts showed expectations for a 10 percent rise in September to about 1.25 million vehicles industry wide.
Ford sales fell 3 percent, to 180,175, as the automaker slowed production of the F-150 pickup truck, the best-selling vehicle in America, to prepare for the launch of the redesigned 2015 model. Analysts surveyed by Reuters expected a similar decline.
F-150 sales dipped 1 percent, with Ford's small cars and crossovers showing bigger declines. Ford's Lincoln brand jumped 13 percent, bolstered by the new MKC compact crossover.
On Monday, Ford slashed its profit outlook for 2014, blaming higher recall costs in North America and steeper losses in Russia and South America. It also offered a disappointing 2015 profit forecast.
GM sales increased 19 percent, to 223,437, about what analysts predicted. The automaker's full-size Chevrolet Silverado and GMC Sierra pickups soared 47 percent to 66,939.
The firm's premium Cadillac brand was flat, but GM said it plans to introduce four new vehicles in North America in 2015 under the label, including the CT6 Sedan.
Read MoreWhy Ford's F-Series launch is crucial
Globally, the Detroit-based automaker said it expected about 27 percent of sales volume to come from new and refreshed products in the next year-and-a-half. GM expected global sales volume to rise 38 percent in 2016 and 2017, and 47 percent in 2019. By 2020, GM said it expects about 99 percent of global production will be on core vehicle platforms.
GM added at its investor meeting that in 2016 it would ring up its first profits in Europe in more than a decade and hit targeted North American operating margins.
The firm said the $1.5 billion in improved operating results in Europe by 2016 includes elimination of $700 million in restructuring costs and addition of $400 million from higher sales and market share.
GM added that boosting its North American profit margins include increased profits from new and refreshed vehicles, as well as raw material cost savings.
The No. 1 U.S. automaker also said any cash returned to shareholders would be mostly through increased dividends. In March, it paid its first quarterly common-stock dividend in almost six years. Some analystshad speculated GM might offer a broad stock buyback program,tapping its $39 billion in cash and equivalents.
GM did not provide an update for its overall 2014 financial results. It said in June and affirmed in July that it was running on or ahead of pace for its previously disclosed plan to report modestly better 2014 operating earnings. Last year, GM's operating profit was $8.6 billion.
Chrysler said sales rose 19 percent, to 169,890. Analysts expected a 17 percent rise. Its Jeep and Ram brands were up 47 percent and 35 percent,respectively, but sales of Jeep Grand Cherokee fell 14 percent.
Nissan sales climbed 19 percent, to 102,955. Analysts looked for a 15 percent increase. The company's premium Infiniti brand fell 13 percent, while sales of the Nissan Leaf electric car jumped 48 percent.
Toyota sales fell 2.5 percent rather than gaining an expected 6.9 percent.
While the forecasts are for another robust sales month, some analysts were concerned that generous consumer deals, including low lease rates and zero-percent financing, are stealing demand from the future.
Each month, auto sales are an early indicator of U.S. consumer demand, particularly for large-ticket items.
Read MoreA start-up that wants to insure your car...cheaply
On Tuesday, reports showed U.S. consumer confidence fell in September for the first time in five months, and home prices in July rose less than expected from a year earlier, underscoring the unsteady nature of U.S.economic growth.
—CNBC contributed to this report.