The century-old clash between Detroit's auto giants has a new battleground: America's trade war with the rest of the world.
General Motors and Ford Motor have tried to present a united front as they grapple with a chaotic Trump administration trade policy that is costing automakers billions and scrambling the global supply chain.
Behind the scenes, the crosstown rivals are clashing as each company jockeys for tailored tariffs and policies while claiming to be the most American automaker.
They are pleading their cases to policymakers, with each trying to stake a claim as being most fundamental to the U.S. economy, as talks intensify around overhauling a North American trade deal crucial to each's business model.
Ford, for instance, wants higher tariffs on imports from South Korea, where GM builds its most inexpensive cars. GM is targeting aspects of Ford's electric-vehicle battery strategy.
The friction reflects how fundamentally different the two Detroit giants have become as diverging manufacturing footprints and supply chains have led them to seek contrasting favors in Washington.
"There was a day when you had the Big Three, and they acted monolithically," said Patrick Anderson of Anderson Economic Group, a Michigan-based consulting firm. "Those days are long gone."
Trade, he said, is especially thorny because it's political in nature.
GM, in a statement, said vehicles made with North American labor and parts should receive preferential tariff treatment, and that it's encouraged by progress made on trade. "Ultimately, this isn't about one automaker vs another; it's about ensuring our country and industry win long-term."
Ford touted its position as the country's top vehicle manufacturer and employer of hourly auto workers. "The Administration and Congress continue to be collaborative partners to ensure that Ford's massive investment in America continues," the automaker said in a statement.
Friction between the rivals isn't new. Theirs is among the most storied and heated rivalries in Corporate America, exacerbated by their proximity and sheer longevity. Ford was founded in 1903; GM showed up five years later. Their headquarters are separated by 15 miles.
For much of their history, the two moved in tandem on some of their biggest business decisions, from union deals to product lineups. The companies now have contrasting strategies on electric cars, the path to producing affordable vehicles, and the future of battery technology.
GM has been more eager to branch off into defense work, while Ford has pared down its small-car lineup to double down on its most profitable "iconic" vehicles.
Ford employs more factory workers and assembles more cars in the U.S. than any of its competitors; some 80% of the vehicles it sells in the U.S. are built there.
It is a point company executives highlight as they argue for higher tariffs on imported vehicles, particularly those from South Korea. That is where, they note, GM builds some 400,000 vehicles a year that it imports into the US -- some of its most affordable models, but ones with already-thin profit margins.
Ford, meanwhile, wants lower duties on imported parts and materials, especially aluminum, which is subject to 50% duties. Ford is the industry's biggest buyer of aluminum, which it uses for the bestselling F-150 pickup, and it has been forced to rely more heavily on imported aluminum after factory fires sidelined its biggest supplier. Administration officials have so far rebuffed Ford's pleas on the issue.
GM makes a different case. The company argues that Ford relies on foreign parts and on Chinese technology for its electric-vehicle batteries. It is GM, they say, that is the bigger overall contributor to the U.S. workforce, when factoring in salaried employees as well as hourly workers. And that the pint-size SUVs that GM imports from South Korea are popular and accessible to everyday buyers.
GM last year tried to block federal funding for a huge Ford battery factory in Michigan, and continues to chide the other automaker for its reliance on Chinese battery technology. While GM is temporarily importing Chinese batteries to help keep costs down on its Chevy Bolt EV, it is scaling its own battery program and developing low-cost batteries in-house.
"We are not licensing somebody else's technology from China. We're building on GM battery know-how in America," Kurt Kelty, GM's vice president of batteries and sustainability, said in June as the company rolled out a plan to develop its own sodium-based batteries.
The companies have clashed over a bill from Sens. Bernie Moreno (R., Ohio) and Elissa Slotkin (D., Mich.) that would ban internet-connected Chinese vehicles from the U.S. market.
While the bill in its current form would ban many Chinese electric-vehicle components, it doesn't include batteries themselves, allowing Ford to keep its battery venture in Michigan with Chinese firm CATL. GM has criticized that point and pushed for the bill to be changed, said a person familiar with the situation.
On one critical issue, the reworking of the U.S.-Mexico-Canada Agreement, the automakers are presenting a united front behind the scenes. Ford and GM, along with Jeep and Ram owner Stellantis, have all pressed the Trump administration to renew the continental trade deal and provide lower tariffs for cars and parts from North America than for the rest of the world, say people familiar with the conversations.
Auto industry trade groups have also advocated for the U.S. government to increase auto tariffs on overseas trading partners -- particularly East Asian economies such as Japan and South Korea -- whose cars remain competitive with many North American-produced models despite tariffs of 15%.