Alex Tremulis (far left) looks on as the X 100 strives for 100 miles per gallon on August 5, 1980.


Subaru 100 MPG Car Revisited


Part One of “A Peek in the Attic” prompted letters and e-mails.


The article also awakened memories in a number of Subaru employees, both current and retired, concerning the X 100 – a Subaru test vehicle that achieved 100 miles per gallon. Here are their clarifications and added facts about the car:


  • It was built by the staff of the Subaru Technical Center in Santa Ana, California
  • On August 5, 1980, testing at the one-mile Ontario Motor Speedway in California – not in Japan, as noted in the last issue – yielded 100 miles per gallon (100.85 mpg, to be exact)
  • The average speed was more than 55 mph – 55.19 mph according to Kyuichi Ikari and 56.4 mph according to Walter Biggers
  • The test driver was Subaru engineer Ron Jones
  • The Gyronaut X 100 was designed by Alex Tremulis, a design consultant for Subaru. (His resume includes involvement with the 1940 Packard Clipper, 1940 Chrysler Thunderbolt concept car, Tucker “Tin Goose” in 1948, and Kaiser-Frazer vehicles of the late 1940s and early 1950s. He headed Ford Advanced Design for 12 years before starting his consulting firm in the 1960s. Besides the X 100, he helped design the Subaru BRAT. See his 1981 design for a production three-wheel X 100 in the Summer 2006 online exclusive by clicking here.)


Drive thanks these people for sharing memories of the Subaru Gyronaut X 100 MPG car:


  • Roger Banowetz, Subaru Research and Development, Inc., Cypress, California 
  • Walter D. Biggers, Spokane, Washington (former Subaru Technical Center Staff)
  • Kyuichi Ikari, Ota-city, Gunma, Japan (Ex. Chief Designer, Design Department, Fuji Heavy Industries, Ltd.)


Alex Tremulis (far left) looks on as the X 100 strives for 100 miles per gallon on August 5, 1980.


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