The Rotax 915 iS engine is delivering better than promised performance, Marc Becker, manager, aircraft business for BRP-Rotax in Gunskirchen, Austria, told attendees at this year's Sun ’n‘ Fun.
“We promised 136 hp, but in fact, the engine is developing 141 hp in the editions we are delivering today,” he told AIN. “Because of the 915 iS turbocharging, we can beat the 180 hp normally aspirated engine from 9,000 feet on up.” The engine provides full sea level power up to 15,000 feet msl. Critical altitude for the engine is 23,000 feet. Becker noted that fuel consumption will depend on the installation. At 5000 rpm and 81kW power, the engine uses 4.6 gallons per hour of avgas, according to test data.
Bryan Toepfer, operations manager for California Power Systems (CPS), a Rotax West Coast U.S. service center and dealer, told AIN, “The interest in the 915 iS has been phenomenal. We are seeing a big explosion in the STOL market, because the engine gives these airplanes increased power with reduced weight, which is just what they need. We delivered the first engine last month, and they are just rolling out the door now. One manufacturer saved about 115 pounds by replacing a 180-hp engine with the 915 iS. The turbocharging means it can maintain the power at altitude into and out of mountain strips.”
Becker said that out of 180 engines delivered so far in the U.S., roughly 100 have gone directly to customers. The engine can be seen performing in a Rans S-7 in Paradise City during Sun ’n‘ Fun 2018.