But putting in a bid won't be simple. The Postal Service wants a van with right-hand drive, which could make it tougher to satisfy U.S.-content procurement rules. The agency also plans to explore alternative-fuel powertrains to save fuel and wants major modifications to suit mail carriers' daily routine and durability standards.
It can't be "something you could just purchase off the shelf," said Jackson, the IHS analyst.
Postal Service procurement rules give preference to products made with at least 50 percent domestic content, said David Hendel, a Washington lawyer at Husch Blackwell who specializes in those rules. But he said the definition of "domestic" has been widened to include many U.S. trade partners, including Canada, Mexico and nearly all of Europe.
In a statement, Ford declined to say whether it will put in a bid.
"While we do not speculate on potential customer orders, we are proud that Ford has been America's best-selling commercial truck brand for 29 years," the company said.
"We offer the broadest commercial vehicle lineup of any manufacturer, from Classes 1 to 7, delivering commercial-grade solutions that can be tailored to meet a wide variety of business or fleet needs."
Among Asian automakers, the most natural fit would be Nissan, which sells the Mexico-built NV200 van in the U.S. But the Japanese automaker said it has no interest in putting in a bid and isn't certified to pursue federal contracts.
Daimler said in October that it plans to shift some production of the next-generation Sprinter van from Germany to North America. It assembles them in South Carolina from kits shipped from Germany to avoid U.S. tariffs.
During its tie-up with Chrysler, Daimler sold Sprinter vans in the U.S. under the Mercedes-Benz and Dodge brands. Now it offers them under the flag of Freightliner, which Daimler bought in 1981.
Freightliner-badged Sprinters are preferred by U.S. government buyers, not only because of Freightliner's American heritage but because Mercedes' posh three-pointed star might give the impression of government waste.
The Postal Service is jumping through a few hoops of its own to make the vehicle purchases possible. The federal agency turns a profit on an operating basis but has projected losses of $6.1 billion for 2015 because of an unusual mandate from Congress that it prepay health benefits for future retirees.
After nearly exceeding its debt limit in an attempt to make those payments, the Postal Service started skipping them without repercussions, said Ruth Goldway, a member of the Postal Regulatory Commission. (President Barack Obama has signaled through the federal budget that the payments may be deferred.)
Goldway said the agency should now be able to afford a next-generation fleet.
"They have to afford it," she said. "They cannot continue as an effective delivery and logistics network without a new vehicle fleet."
Ryan Beene and Lindsay Chappell contributed to this report.