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.

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.

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. M264

Please be sure to visit JB4tech.com for the latest map guide, firmware updates, installation directions, and notes: https://www.jb4tech.com/forum/model-specific-engine-tuning-modification-discussion/mercedes-c250-c300-c43-amg/3466-mercedes-c300-c400-c450-c43-w205-jb4

Wirelessly Connect to your JB4: Our all-new JB4 PRO smartphone connection is included to wirelessly connect the JB4 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 information about the JB4PRO mobile app click here.

JB4 Features & Benefits

• Power gains range from 30-60whp on pump gas and much more on higher octane or E85 mixtures.
• Improves 0-60 and quarter mile times.
• Includes multiple tuning maps for different fuel types.
• Quick plug and play installation.
• Supports E85 ethanol blends.
• Reads and deletes fault codes.
• Displays and logs up to 40 engine parameters.
• Boost by gear control for improved traction.
• Controls exhaust flap operation on supported vehicles.
• Compatible with the free JB4PRO app.
• Offers better performance and safety than basic chip tunes.
• Full CANbus integration.
• Runs as smoothly as stock.
• Compatible with all driving modes.
• No impact on fuel economy during normal driving.
• Requires 91 octane or better for performance gains.
• Not VIN locked and fully removable.
• Includes billet aluminum enclosure.
• Designed and assembled in the USA.
• 5-year warranty.

Vehicle Fitment

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

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 and is sold in over 67 countries worldwide.

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.

All 2015-2018 and non-C300 2019+ Mercedes-Benz

2019+ C300/GLE Mercedes-Benz (SENT)

DYNO RESULTS

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

2020 C43 JB4, BCM, 30% E85