I’m saddened to have to add an asterisk to the legacy of Buckminster Fuller. The marvelous American polymath and architect made claims about his Zeppelin-like Dymaxion car in 1933 that appear now to have been exaggerated, based on my experience in a new, faithfully reproduced Fuller death-mobile.

The vehicle I drove last week is a museum-quality copy of Dymaxion #1, one of three vehicles designed by Fuller and built by the 4D Company in Bridgeport, Conn., in the early 1930s. Jeff Lane, founder of the Lane Motor Museum in Nashville...