Japanese bemused by Trump bowling ball car test claim
President of the United States Donald Trump speaking at the 2018 Conservative Political Action Conference (CPAC) in National Harbor, Maryland. (Gage Skidmore/Flickr)

A claim by President US Donald Trump that Japan tests car quality by dropping bowling balls on vehicles has prompted confusion and ridicule among some Japanese.

The Washington Post reported Thursday that Trump claimed in a fundraising speech that Japan was using unreasonable testing standards to keep out US auto companies.

"They take a bowling ball from 20 feet up in the air and they drop it on the hood of the car," Trump reportedly said.

"And if the hood dents, then the car doesn't qualify. Well, guess what, the roof dented a little bit, and they said, nope, this car doesn't qualify. It's horrible, the way we're treated. It's horrible."

Several Japanese media outlets picked up the Post report, and Japanese Twitter users reacted with confusion and derision.

"Stupid Trump... says Japan carries out a test dropping a bowling ball on cars," wrote user @BlackTower_B.

"It's too stupid for words."

Others laughed off the bizarre assertion, with @technopolis writing: "if there is a car which won't dent after a bowling ball falls on it from six metres up in the air, I want that car!"

White House spokeswoman Sarah Huckabee Sanders told reporters that Trump was "obviously... joking".

But that did little to tamp down speculation about where Trump came up with the idea of the test.

Some pointed to a method that is used by Japan's Nation Agency for Automotive Safety and Victim's Aid to test the potential impact of a car accident on a pedestrian.

Adult- and child-sized "head impactors", which resemble bowling balls with the bottom third sliced off, are fired towards car hoods and other areas.

"The impact received by the head impactors is measured and then evaluated using head injury criterion," NASVA says on its website.