High gasoline prices are taking a toll on General Motors and Ford.
The nation's two biggest automakers saw sales fall again in May as customers continued to turn away from sport utility vehicles and trucks in favor of rivals' cars.
GM's car sales fell 1.5 percent and truck sales were down nearly eight percent.
At Ford, the number-two carmaker behind GM, new vehicle demand fell for the 12th straight month. Sales slipped nearly three percent in May.
By contrast, Toyota's total sales rose nearly eight percent with car sales faring well in the face of flat truck sales.