JB4 Performance Tuner for 2014+ Mercedes-Benz

Unlock hidden performance from your turbocharged Mercedes-Benz.
The JB4 Performance Tuner is the most advanced plug-and-play tuning system available for modern Mercedes-Benz turbo vehicles. Designed to work seamlessly with your factory ECU, the JB4 safely increases boost, optimizes timing and fueling, and delivers substantial horsepower and torque gains—while maintaining factory-smooth drivability.

🔥 Proven Power Gains

• Up to +50 WHP on C300 models
• Up to +120 WHP on C400 / C450 models
• Up to +80 WHP on C43 AMG models
• Even greater gains possible with race fuel or E85 blends

Boost pressure is safely increased by approximately 3–6 PSI, with timing and fueling intelligently rescaled to maintain reliability.

🔌 True Plug & Play Installation

The JB4 installs in minutes using easy-to-access connections on top of the engine. No cutting, no splicing, and no permanent modifications.

• Completely reversible installation
• Compatible with AWD and RWD vehicles
• Works with factory ECU and all driving modes

🧠 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 adjustments for smoother, safer, and more powerful performance.

• Fuel and spark control for safe high-power operation
• Improved performance and drivability vs. non-integrated chip tunes
• Optional BCM support for advanced boost control

📱 Smartphone Connectivity & Datalogging

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

• Change 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 features and maps are released
• Measure 0–60 performance

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

🏁 JB4 Exclusive Performance Features

• Up to 8 preloaded tuning maps
• Ethanol (E85) compatible maps
• User-adjustable boost-by-gear (1st, 2nd, 3rd)
• Valet mode with reduced power
• Exhaust flap control on supported vehicles

🚗 Mercedes-Benz Vehicle Fitment

A-Class

• 2018+ A220 (W177)
• 2018+ A250 (W177)

B-Class

• 2014+ B250

C-Class / CLA / CLS

• CLA 250 (C117)
• CLS 400 (W218)
• C200, C250, C300 (W205)
• C400, C450 (W205)
• 2015–2022 C43 AMG (W205)

E-Class

• E300 (W212 / W213)
• E400 (W212)
• E43 AMG (W212)

GLA / GLC / GLE

• GLA 250
• GLC 250 / 300 / 43 AMG
• GLE 250 / 300 / 350 / 43 AMG

S / ML / V-Class

• SLC 43
• ML 400 (2015–2019)
• Metris, V-Class, Valente, Viano (W447)

⚠️ Important Notes

2019+ C300 models use updated SENT pressure sensors and require a specific JB4 version. Please confirm vehicle details prior to ordering. Compatibility information will be updated as new model data becomes available.

✅ JB4 Features & Benefits

• 30–70+ WHP gains depending on model
• Improves acceleration and quarter-mile times
• 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
• 5-Year Manufacturer Warranty

❓ 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 performance while monitoring critical engine data via CANbus.

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.