DETROIT – Another milestone in the decades-long decline of Detroit’s automotive giants arrived unexpectedly on Tuesday as Toyota Motor Co. surpassed Ford Motor Co. in U.S. monthly vehicle sales for the first time, by a margin of 1,837 vehicles.

Americans’ growing preference for foreign models and more fuel-efficient vehicles also pushed Honda Motor Co.’s sales past the Chrysler Group for the first time, by an even slimmer margin of 1,455 vehicles. Including Mercedes, DaimlerChrysler held onto fourth place.

General Motors Corp. found more good news in the results than its competitors, improving its U.S. market share from earlier this year and gaining traction with new models. But at Ford and Chrysler, a dearth of new vehicles combined with the crush of gas prices sent more buyers searching for alternatives.

The shifts reflect a market that shrunk 17 percent from a year ago, when Detroit’s automakers attracted record numbers of buyers with employee pricing promotions. Last year’s blowout made comparisons ugly, with GM sales down 22.5 percent, Ford off 34 percent and Chrysler down 37 percent.

Since last year, GM has pulled back from nonstop incentive hawking, preferring to lower prices and promote the qualities of its vehicles even at the expense of some sales. Ford indicated on Tuesday it would take a similar tack, halting its national incentives in favor of regional ones. Chrysler went against the grain, due in part to swollen inventories, saying it would maintain a mix of employee pricing, rebates and cheap loans through the end of August.

All of those programs have failed to reverse the slow erosion of market share from Detroit to foreign competitors, and foreign automakers claimed 48 percent of the U.S. market in July.

Toyota did not flag its sales victory, and a Toyota spokesman said the company was unaware it had passed Ford until reporters started calling for comment. Ford’s year-to-date total is still greater than Toyota’s by about 318,000 cars and trucks, and Toyota says its title as the No. 2 U.S. automaker may be short-lived.

“We’re in a lucky situation,” said spokesman Mike Michaels. “Our product has moved to the market just as the market has moved to our products.”

Only subscribers are eligible to post comments. Please subscribe or to participate in the conversation. Here’s why.

Use the form below to reset your password. When you've submitted your account email, we will send an email with a reset code.