Mercedes-Benz S-Class / AMG GT / SL / CLS Custom HP Tuners Tuning (3.0L I6 M256 / 4.0L V8 BiTurbo M177 & M178)

Our HP Tuners custom calibrations for the Mercedes-Benz S-Class, AMG GT, SL, and CLS are engineered to unlock the full performance of the 3.0L I6 M256 and 4.0L V8 BiTurbo M177/M178 engines. From refined luxury sedans to AMG supercars, our in-house tuning sharpens throttle response, increases horsepower and torque, and refines drivability — while maintaining Mercedes-AMG reliability.

Key Features

• Engine Coverage

  • 3.0L I6 Turbo (M256, w/ EQ Boost) – Found in select S-Class, CLS, and SL models (2018–2023)

  • 4.0L V8 BiTurbo (M177) – Found in AMG S-Class, CLS 63, SL 63, and other AMG performance sedans/coupes (2015–2023)

  • 4.0L V8 BiTurbo (M178) – Exclusive to AMG GT models (2015–2023, including GT S, GT C, GT R, GT Black Series)

• Transmission Support – Calibration for AMG 7-speed, 9-speed, and DCT gearboxes, refining shift timing, torque management, and launch control

• Custom Calibration – Adjustments for intakes, intercoolers, downpipes, exhaust systems, turbo upgrades, fueling enhancements, and flex-fuel/E85 conversions

• Safe Performance – Tunes engineered for knock-safe ignition, optimized fueling, and smooth drivability in all conditions

• Remote Tuning – Fully supported via HP Tuners MPVI2 and MPVI3 for secure file exchange and flashing

Benefits

• Faster throttle response with reduced turbo lag

• Horsepower and torque gains across the powerband

• Stronger mid-range acceleration and higher top-end output

• Improved transmission response for both luxury cruising and spirited driving

• Reliable calibration for stock and performance-modified AMG builds

Compatibility

Custom tuning is available for:

• Mercedes-Benz S-Class (M256 I6 & M177 V8, 2015–2023)

• Mercedes-Benz AMG GT (M178 4.0L V8 BiTurbo, 2015–2023)

• Mercedes-Benz SL-Class (M256 I6 & M177 V8, 2016–2023)

• Mercedes-Benz CLS-Class (M256 I6 & M177 V8, 2015–2023)

Process

1. Purchase your Mercedes-Benz custom tuning package.

2. Use HP Tuners to read your factory ECU calibration.

3. Provide your stock file and modification list.

4. Receive a calibration tailored to your exact build.

5. Flash your tune and enjoy instant improvements.

Professional Assurance

All Mercedes-Benz calibrations are developed in-house with precision, ensuring performance gains that do not compromise drivability or reliability. From luxurious S-Class sedans to track-ready AMG GTs, our HP Tuners custom tuning delivers consistent, proven results across the M256, M177, and M178 platforms.

Meta Description (SEO)

Custom HP Tuners tuning for Mercedes-Benz S-Class, AMG GT, SL, and CLS. Support for 3.0L I6 Turbo (M256) and 4.0L V8 BiTurbo (M177/M178). Improve horsepower, torque, throttle response, and drivability.