Given the vagaries of the world's markets, it is impossible to say with any certainty that Toyota will pass GM in a specific year or even that it will happen at all. But the trend lines are clear: While GM's global share has fluctuated within a fairly narrow range in recent years, the Toyota juggernaut has continued to push ahead - as Ford knows.
Between 1998 and 2002, GM's global sales rose 4.4 percent to 8.50 million, thanks to a sharp rise in 1999 that then eroded over each of the following three years. Conversely, Toyota's global sales during that period rose 16.8 percent to 6.17 million units, or at nearly four times GM's pace.
Of course, trends are not irreversible. Companies that are strong one decade can go into reverse the next. Ford outperformed GM through much of the 1990s, only to stall.
After being the world's No. 1 or No. 2 carmaker almost since its founding, Ford passed two milestones in 2003. It celebrated its centennial, and it fell to No. 3 in the world.
Toyota estimates that its 2003 retail sales topped Ford's, 6.783 million to 6.720 million, or by about 60,000 units. Wholesale figures that Toyota will release on Thursday, Feb. 5, may show a different story, depending on how Toyota tallies factory sales from joint-venture plants around the world.
Accounting regulations say Ford can't count sales by Mazda Motor Corp. because Ford owns 33.4 percent of Mazda rather than a majority. But those rules are not as cut and dried when it comes to joint ventures.
But in the unlikely event that Toyota does not consolidate into its total the more than 300,000 Toyota-badged vehicles it built at its New United Motor Manufacturing Inc. joint venture in Fremont, Calif., in 2003, it would not pass Ford.
Accounting rules aside, though, Toyota had a great 2003, and Ford didn't.
In 2003, Toyota's sales rose in every region of the world. The slowest gains came in North America, where sales rose a mere 6.8 percent compared with a 38.8 percent surge in Asia and an 11.8 percent jump in Europe.