JB4 Performance Tuner for 2023+ Mercedes-AMG C43 & GLC AMG 2.0L Hybrid

Unleash the true potential of your next-generation AMG.
The JB4 Performance Tuner is the most advanced plug-and-play tuning solution available for the 2023+ Mercedes-AMG C43 and GLC AMG 2.0L hybrid platforms powered by the M139 engine. Designed to integrate seamlessly with your factory ECU, the JB4 delivers substantial horsepower and torque gains, sharper throttle response, and reduced turbo lag—while retaining factory smoothness and reliability.

🔥 Real-World Performance Gains

• 30–65 WHP gains on pump gas
• Turbo boost safely increased by approximately 3–6 PSI
• Noticeable improvements in 0–60 and quarter-mile times
• Even higher gains possible with ethanol (E85) blends

Timing and fueling are intelligently rescaled to support the increased boost, ensuring strong, consistent performance without sacrificing drivability.

🔌 True Plug & Play Installation

The JB4 installs in minutes using two easy-to-access connections on top of the engine. No cutting, splicing, or permanent modifications are required.

• Completely reversible in seconds
• Compatible with all factory driving modes
• Runs as smoothly as stock

🧠 Advanced CANbus Integration

Unlike basic two-channel tuning devices, the JB4 features full CANbus OBDII integration, allowing it to monitor real-time engine data and make intelligent tuning adjustments.

• Smoother, safer, and more powerful performance
• Improved drivability over non-integrated chip tunes
• Fuel and spark control for reliable high-output operation

📱 Smartphone Connectivity & Datalogging

Pair your JB4 with a compatible Bluetooth adapter to unlock full wireless control via your iOS or Android device.

• Switch performance maps on the fly
• View and log up to 40 engine parameters in real time
• Read and delete diagnostic fault codes
• Update firmware as new maps and features are released

JB4 Mobile app sold separately ($29). Bluetooth adapter required.

🏁 JB4 Features & Benefits

• Up to 8 preloaded tuning maps
• Ethanol (E85) compatible maps
• User-adjustable boost-by-gear (1st, 2nd, and 3rd)
• Fuel economy unchanged during normal driving
• 91 octane or higher recommended
• Not VIN-locked – transferable or resellable
• Removable with no trace
• Rugged billet aluminum enclosure
• Made in the USA
• Free USA Shipping
• 5-Year Manufacturer Warranty

🚗 Vehicle Fitment

• 2023+ Mercedes-AMG C43 2.0L Turbo Mild Hybrid (M139)
• 2023+ Mercedes-AMG GLC AMG 2.0L Turbo Hybrid (M139)

❓ What Is a JB4?

The JB4 is an advanced plug-and-play tuning system for turbocharged vehicles. It installs between your engine sensors and ECU, intelligently increasing boost while monitoring critical engine data through CANbus for unmatched performance and safety.

Often imitated but never duplicated, the JB4 has been the gold standard in plug-and-play turbo tuning for over a decade and is trusted by enthusiasts in more than 67 countries worldwide.