What is the most powerful Rotax engine

The strongest production Rotax you can buy right now? That's the Rotax 916 iS. It's a turbocharged, fuel-injected four-stroke that throws down 117 hp (87 kW) continuous and peaks at 121 hp (90 kW) for takeoff. This thing is basically the top dog of Rotax engineering—built for high-performance Light Sport Aircraft, experimental builds, and ultralights that demand real muscle. The 916 iS kicked the old king, the Rotax 915 iS (which does 135 hp but only at lower altitudes), off the throne by offering way better power density and high-altitude chops thanks to its fancy turbo system.

What makes the Rotax 916 iS the most powerful?

So how does the 916 iS pull ahead? It's all about the tech stack. The secret sauce is that turbocharged and intercooled induction system. Regular engines? They choke as you climb. But the 916 iS just keeps on trucking—full power all the way up to 15,000 feet (4,572 meters). There's also a sophisticated ECU that handles fuel injection and ignition timing, squeezing every bit of performance and efficiency out of the engine across the whole flight envelope. The payoff? A power-to-weight ratio that's frankly nuts for this class—over 1 hp per kilogram of engine weight.

How does the Rotax 916 iS compare to other powerful Rotax engines?

To really get the picture, you gotta stack it up against its siblings and predecessors. The 915 iS was the champ for a while, but the 916 iS is the new sheriff. Here's how they shake out.

See, the 916 iS isn't just about raw numbers—it's about keeping that power when you're up high. The 915 iS hits a higher peak on paper, but it can't hold that at altitude like the 916 does. Plus, the 916 gets a redesigned turbo and better cooling, so it's more reliable when you're really pushing it hard for a long time.

What are the best applications for the Rotax 916 iS?

This engine really shines in aircraft that need to perform—especially at altitude. Some common places you'll find it:

• High-performance Light Sport Aircraft (LSA): Birds like the Zlin Savage and Flight Design F2 are running the 916 iS now, getting better cruise speeds and climb rates.
• Experimental and Kit Aircraft: Builders who want a powerful, reliable, lightweight option often pick the 916 iS for designs like the Sling TSi or Rans S-21.
• Ultralight and Trike Aircraft: It's light—about 72 kg with the gearbox—so it's perfect for weight-sensitive ultralights, letting you carry more stuff and fly better.
• High-Altitude Operations: If you're flying in mountains or out of high-elevation airports, that constant power output is a huge safety and performance boost.

Frequently Asked Questions about the most powerful Rotax engine

Checklist: Key considerations before choosing the Rotax 916 iS

Before you pull the trigger on the most powerful Rotax, run through this list:

• Airframe compatibility: Make sure your aircraft is certified or designed for the 916 iS. Not every LSA or experimental airframe is okay with this engine.
• Weight and balance: The 916 iS is heavier than a 912 iS. Double-check your aircraft's CG limits can handle the extra weight.
• Propeller choice: You'll want a constant-speed or ground-adjustable prop to really use that power band.
• Cooling system: Turbo engines run hot. Make sure you've got enough radiator and oil cooler capacity.
• Budget: Don't just think about the engine price—installation, prop, and any airframe mods add up fast.
• Maintenance support: You'll need a Rotax-trained mechanic who knows the 916 iS's specific quirks.