Power gains are up to 50whp for the C300, up to 60whp for the C400/C450, and up to 70whp for the C43. On racing fuel or E85 mixtures even higher gains are possible.

This quick install plug and play tuner connects to easy to reach plugs on top of the engine and safely increases turbocharger output by 3-6psi producing significant power and torque increases. Timing and fueling are appropriately rescaled for the increased boost and the installation is completely reversible in seconds. Compatible with all wheel drive and rear wheel drive models. The JB4 is the only tuning system that includes CANbus and optional BCM connections providing dramatically improved performance and smoothness over other 2-channel tuning systems.

Note 2019+ C300 models have changed to new SENT pressure sensors and require a unique JB4 system. Right now we believe all other 2019+ systems, C400, C450, C43, etc, continue to use the older pressure sensors but expect they will also migrate over at some point in the future. We'll update the model year compatibility details as we receive them.

If you want extra ordinary performance buy air intake also. For M264, M276, M274 Engine.

Please be sure to visit JB4tech.com for the latest map guide, firmware updates, installation directions, and notes.

Wirelessly Connect to your JB4: Grab our all-new JB4 PRO smartphone connection to wirelessly connect the JB4 BMW tuner to your Bluetooth 4.0 compatible iOS or Android device. This option allows you to record and analyze vehicle and tuning data, change JB4 performance maps, and update JB4 firmware as we release free newer versions with updates, more powerful maps, and new features under development. Our new adapter fits fully inside the JB4 enclosure for enhanced weather protection and a more streamlined look. The JB4PRO Free app features an intuitive easy-to-use interface, help buttons, and advanced log analysis tools that can estimate the performance of your car and help identify any tuning concerns. For more info on how to use the JB4PRO free app click here.

JB4 Performance Tuner Features & Benefits

• Power gains range from 30-60whp on pump gas and much more on higher octane or E85 mixtures.
• Improves 0-60 times and 1/4 mile times
• Preloaded with custom JB4 tuning software and up to 8 maps for various fuel and modification levels
• Ethanol (E85) compatible tuning maps
• Able to read/delete fault codes
• View and record up to 40 different gauges/engine parameters in real-time with the JB4 app.
• Boost by gear in 1st, 2nd, and 3rd can be controlled via the JB4 app for a perfect launch
• Exhaust flap operation can be controlled in most JB4 applications
• Compatible with JB4 Mobile for smartphone logging, tuning changes, and adjustment
• The JB4 offers a lot more performance, functionality, and safety than your average performance chip
• Quick Plug & Play Installation
• CANbus OBDII integration offering unrivaled tuning features and performance
• Improved performance over non-integrated chip tunes
• Runs as smoothly as stock, this is how your vehicle should have come from the factory
• Compatible with all driving modes
• Fuel economy unchanged during normal driving
• 91 octane fuel or better required for performance gains
• Not VIN locked and can be removed without a trace and resold down the road
• Includes the rugged JB4 billet aluminum enclosure for protection
• Made in the USA
• 5-year warranty

Vehicle Fitment

If you don't find your vehicle here, please search "mercedes jb4" on our website.

A-Class
• 2018+ Mercedes-Benz A250 W177
• 2018+ Mercedes-Benz A220 W177

B-Class
• 2014+ Mercedes-Benz B250

C-Class
• 2014+ Mercedes-Benz CLA 250 C117
• 2015+ Mercedes-Benz CLS 400 W218
• 2015+ Mercedes-Benz C200 W205
• 2015+ Mercedes-Benz C200 W205
• 2015+ Mercedes-Benz C250 W205
• 2015-2018 Mercedes-Benz C300 W205
• 2019+ Mercedes-Benz C300 W206
• 2014+ Mercedes-Benz C400 W205
• 2015-2022 Mercedes-Benz C43 AMG W205
• 2015+ Mercedes-Benz C450 W205

E-Class
• 2016+ Mercedes-Benz E300 W212
• 2017+ Mercedes-Benz E300 W213
• 2015+ Mercedes-Benz E400 W212
• 2015+ Mercedes-Benz E43 AMG W212

G-Class
• 2016+ Mercedes-Benz GLE 250, 300, 350, 43 AMG
• 2016+ Mercedes-BenzGLC 250, 300, 43 AMG
• 2015+ Mercedes-Benz GLA 250

S-Class
2017+ Mercedes-Benz SLC 43

ML-Class
• 2015-2019 Mercedes-Benz ML 400

V-Class
• 2016+ Mercedes-Benz Metris Van W447
• 2016+ Mercedes-Benz V-Class Van W447
• 2016+ Mercedes-Benz Valente Van W447
• 2016+ Mercedes-Benz Viano Van

If you don't find you model please check here or its better just contact us with your model and year. We will help you identify faster. 

What is a JB4?

The JB4 is a plug & play tune available for turbocharged vehicles. The JB4 tuner installs between your car's sensors and its DME/ECU (computer) and manipulates vehicle performance through these connections making your vehicle much faster. While it's not the only tuning system that operates this way the JB4 separates itself from the competition with much more advanced connection points and processing including CANbus, fuel & spark control, Bluetooth to your smartphone, and a variety of innovative and advanced features not possible with any other system. BMS regularly publishes free mapping and firmware updates adding performance and features as ongoing development allows. In addition, the JB4 system is not VIN-locked to your vehicle and can quickly be removed and swapped between cars or resold at a later time. Often imitated but never duplicated the JB4 has been the gold standard in plug and play turbocharged performance tuning for over a decade.

Is the JB4 a real tune?

Yes the JB4 is a real tune. By tapping into specific sensors and CANbus for real time vehicle data the JB4 is able to alter your boost, timing, AFR, and/or fuel trims, to a similar degree an ECU reflash would, but without the vehicle ever knowing its been tuned. The result is safe, smooth, and significant power and torque gains while retaining your factory safety systems and without having to unlock/flag your ECU.

DYNO RESULTS

2020 Mercedes-Benz C43 AMG Map 5 E30 JB4, BCM, & Intake testing

2020 C43 JB4, BCM, 30% E85