Born in Omaha, Nebraska, Mathouser died in Los Angeles, California. He drove in the USAC Championship Car series, racing in the 1961-1966 seasons, with 30 career starts, including the 1964 Indianapolis 500 where he drove the Dayton Disc Brake Walther/Offy, spinning out after 77 laps. He finished in the top ten 4 times, with his best finish in 6th position in 1964 at Langhorne.
Mickey Thompson brought a front wheel drive car to Indy in 1965, the year after Eddie Sachs and Dave McDonald were killed in the fiery crash. Mathouser drove the car but had an engine failure on his final qualifying run, however the car still holds the IMS front wheel drive, one lap speed record of 153.374.
The slowest car in the field that year ran a 4-lap avg. of 153.770, however there was a miscalculation in the methanol/nitro mix causing it to scattered most of the double overhead cam aluminum small block Chevy engine down the length of the front stretch on the final day of qualifications, otherwise the Mathouser/Thompson car might have qualified. It would have been one of the ugliest cars ever to run at Indy. Front engine, front wheel drive with all-wheel steering, Mathouser sat above the rear axle housing and one cant help thinking that it was a spot of luck that it didn't run. The car still holds the Indianapolis Motor Speedway front wheel drive, one lap speed record at 153.374!