That's according to an estimate by industry consultants Alixpartners on Thursday (September 23).
And it's almost double the estimate made back in May.
The global shortage of computer chips is one problem, but far from the whole story.
Automakers have warned that silicon supplies aren't improving as they'd expected.
Resurgent health worries have hobbled output at key chip producers in Malaysia.
But supplies are also tight for other components, such as steel and plastic resin.
Backlogs at major U.S. ports are hampering efforts to bring in more supplies there.
And prices for parts have risen across the supply chain.
All told, Alixpartners estimates carmakers will lose output of 7.7 million vehicles this year as a result of the problems.
Thursday sees a new plea for help.
Reuters sources say General Motors, Ford and BMW will be among carmakers attending a virtual White House summit on the semiconductor shortage.
Chipmakers including Intel and TSMC will also attend.
They've both pledged to ramp up output, but new chip plants could take years to come on stream.
U.S. legislation to help fund new semiconductor factories is awaiting congressional approval.
