With six months left in 2014, automakers have already recalled more vehicles in the U.S. than in any other year on record.

The National Highway Traffic Safety Administration lists U.S. recalls for 37.5 million cars this year, topping the 30.8 million record set in 2004, according to the most recent preliminary data Monday on the agency's website. General Motors Co. accounts for about two-thirds of the total.

The tally in the U.S. will probably rise soon as Japan's three biggest carmakers finish an evaluation of their worldwide fleets for faulty air-bag inflators made by Takata Corp. Through June, about 8.1 million new vehicles had been sold in the U.S.