What was the secret behind the economy? Well, the wing was a big part of it, and so was the 310 hp Continental six-cylinder TSIO-520 in the airplane. Designed to run efficiently while lean of peak, a foreign concept to many pilots of the day, the engine did just that, giving the Malibu a remarkable range, around 1,500 nm. Now, 310 horsepower doesn’t seem like much, and it isn’t. The Duke, for example, had 70 more horses … per side!