GM sales still fell 18.2 percent compared to last year during a dismal June for most large automakers, the Associated Press reported. Toyota's sales in the U.S. fell 21.4 percent, while Ford said it sales tumbled nearly 28 percent.
Honda, which boasts the most fuel-efficient vehicle line-up among the major automakers, bucked the downturn and posted a 1 percent sales gain.
Chrysler posted the most dismal numbers, seeing its U.S. sales drop 36 percent. The company's car sales were down nearly half and truck sales were down by nearly a third since last year.
"The June results reflect the industry-wide impact of U.S. consumer confidence being at its lowest point since 1992," said Jim Press, a Chrysler president and vice-chairman, according to the Detroit Free Press.
The automaker also announced it will extend its $2.99 gas guarantee incentive program through July 31.
GM shares, which sunk to a 54-year-low Monday and have trended lower for two months, jumped on the June sales numbers and pulled the broader U.S. equity market higher.
"We felt that was a very successful month-end merchandising program," GM's North American sales chief Mark LaNeve told Reuters, referring to its interest-free loan deal. "It was six days long and really helped build dealer and customer momentum."
As expected, sales for pickup trucks and SUVs sank sharply. That was only partly offset by stronger sales of small cars and vehicles with more fuel-efficient four-cylinder engines.
George Pipas, the top sales analyst for Ford, said SUV sales are probably down for good.
"Our view is that gas prices aren't likely to go down, and more importantly, many consumers have moved on," he told the AP. "We believe that the segment has merit for certain consumers but is not likely to rebound at any point."
Before the dreary June numbers were released, U.S. auto sales had already fallen for seven straight months as of May, the longest period of consecutive monthly drops in eight years, Edmunds.com reported.
When customers do buy, they're picking smaller cars, crossovers and hybrids. Ford said sales of its smallest car, the Ford Focus, rose 28 percent in the first six months of the year, although Focus sales fell in June.
Creditors and investors want to know whether the cash-strapped U.S. auto industry is headed for an even worse second half for sales, weighed down by the continued housing slump, tighter credit and high gas prices.