Both Johnson and Lear had contemplated constructing steam-powered cars for the Indy 500, Johnson first in the early 1960s when with Controlled Steam Dynamics and in 1968 with Thermodynamic Systems and Lear in 1969. A third steam racing car was contemplated by a consortium of Planning Research Corporation and Andy Granatelli of STP Corporation. Lear proceeded with the idea and constructed a car, but ran out of funds while trying to develop the engine.