2015-2021 Mercedes C300 ECU Tune GLC300 E300 – M274 2.0 Turbo

A custom ECU calibration for the Mercedes-Benz M274 2.0L turbocharged four-cylinder, written around your specific car, fuel and hardware rather than pulled off a shelf. Sharper throttle, stronger mid-range torque, and cleaner power delivery — with every factory safety system left intact.

Up to 320 hp / 340 lb-ft on a Stage 2 setup — calibration running with supporting bolt-ons (catless downpipe and high-flow intake filter). Tune-only output is lower and varies with fuel grade, ambient conditions and the hardware already on the car.

What the Tune Delivers

• Stronger mid-range torque — where the M274 actually lives in street driving
• Sharper throttle response — reduced pedal lag and quicker boost onset
• Refined boost and torque control — smoother delivery under load, not just a taller peak
• Better part-throttle drivability — improved cooperation with the transmission in normal driving
• Factory safeguards retained — knock control, thermal limits and torque protection all remain active

Vehicle Compatibility

RWD and 4MATIC both supported.

What's Included

• Custom ECU calibration developed for your car, fuel grade and modification list
• OBD flashing cable and handheld programmer
• Return-to-stock file
• Direct support through the flash process

Off-road use only. Not legal for use on emissions-controlled vehicles or public roads.