STIHL Fuel Injection Technology

STIHL’s Fuel Injection Technology is a fully electronic system that delivers the optimal amount of fuel directly to the combustion chamber — ensuring powerful performance, fast acceleration, and exceptional efficiency. Unlike carburetted engines, there’s no need for manual adjustments or choke levers.

This cutting-edge system was first introduced in the STIHL MS 500i — the world’s first chainsaw with electronically controlled fuel injection. It automatically adapts to environmental conditions such as altitude, temperature, and fuel quality, delivering consistent performance every time.

The engine’s microprocessor calculates the precise fuel dose and ignition timing in real-time using data from multiple sensors. This ensures efficient combustion and instant throttle response.

• Fuel is injected directly into the crankcase with millisecond precision.
• Sensors monitor air pressure, temperature, and engine speed continuously.
• The ECU adjusts mixture and timing dynamically for optimal performance.
• No carburettor, no choke — automatic adaptation to conditions.

STIHL’s EFI system provides several key benefits over traditional carburettor-based engines:

• Instant acceleration: Direct fuel injection eliminates lag.
• Consistent power: Automatic adjustment to altitude and temperature.
• Reliable cold starts: No choke required — starts easily every time.
• Improved fuel economy: Up to 15% more efficient combustion.
• Reduced emissions: Cleaner, more precise burning of fuel.

Watch how STIHL’s electronically controlled fuel injection delivers maximum precision and responsiveness.

• Electronic control: Real-time fuel and ignition management.
• Automatic adaptation: Altitude, temperature, and load optimised instantly.
• Reliable starting: No choke, no adjustments needed.
• More power, less fuel: Efficient and eco-friendly combustion.
• Exclusive to STIHL: First in the world to use EFI in handheld tools.