The Detroit 3 think relieving the soaring price of health insurance could be one of the most effective ways to curb labor costs.
The UAW, meanwhile, insists on preserving the generous plans that allow many members to pay little or no premiums, copays and deductibles.
Those opposing viewpoints could make health care one of the most divisive issues in this year's national contract negotiations, which formally begin this week. A previous joint effort between the two sides on insurance reform, as well as brief flirtations with a co-op in 2015, could leave room for collaboration.
But it will be a tough road to reach a compromise.
Union leaders, still acutely aware of painful concessions made during the Great Recession, view health care as a virtually untouchable benefit.
The automakers, however, will argue that failure to rein in ballooning costs could threaten what money would be available to invest in future jobs and product.
"I don't think the UAW wants to take any concessions but I don't think they want to see their plants closed either," Art Wheaton, a labor expert at Cornell University, told Automotive News. "It's one of the biggest bread-and-butter issues on the table. It's not an easy one to touch, but there's room for savings."
The auto companies hope so.
Ford Motor Co.'s annual cost to provide health care to its hourly workers and their dependents will surpass $1 billion next year, according to a source familiar with the situation. Costs at General Motors and Fiat Chrysler Automobiles are increasing to similar figures.
If nothing changes at Ford, inflation costs alone over the next four years would be equivalent to a nearly $3-an-hour pay increase, the source said.
And a potentially crippling wild card looms next decade: a 40 percent "Cadillac tax" on rich plans such as the UAW's under a provision in the Affordable Care Act that's to take effect in 2022, although that deadline has been pushed back in the past.