On April 29, 1930, the new Henderson "Special" KL solo was demonstrated on a new, smooth concrete Illinois highway. Joe Petrali achieved 116.12 mph and 109.09 mph on two recorded runs, averaging 112.61. The higher compression two-ring pistons, and an enlarged 1.25 inch (32 mm) carburetor, meant the KL engine produced 45 hp at 4,500 rpm. The KL was remarkably flexible in top gear, pulling smoothly from 8 to 110 mph. They were even more popular with police departments in the United States.