JB4 Performance Tuner for BMW GEN3 B48/B58 Engines

Unlock the full potential of your BMW with the latest JB4 Performance Tuner engineered specifically for GEN3 B48 and B58 engines. Designed, tested, and manufactured in the USA, the JB4 delivers industry-leading power gains, advanced CANbus integration, and unmatched reliability—all in a plug-and-play package that installs in minutes and can be removed without leaving a trace.

Utilizing proprietary JB4 tuning software and up to eight selectable maps, this system dramatically enhances performance while maintaining smooth, factory-like drivability. Whether your BMW is stock or modified, running pump gas or ethanol blends, the JB4 provides the tuning flexibility and data control needed to achieve the perfect setup.

Exceptional Power Gains

Experience real, dyno-proven performance with up to 130whp gained on an otherwise stock vehicle. Acceleration improves noticeably with faster 0–60 mph and ¼-mile times, making your BMW feel as though it should have come from the factory with this level of performance.

Advanced Tuning Features

The JB4 provides far more capability and safety than typical plug-in chips, thanks to deep CANbus OBDII integration. Monitor over 40 engine parameters in real time through the JB4PRO app, adjust maps, control boost by gear, and customize settings for your driving style. Ethanol-compatible tuning maps (including E85 mixtures) offer even greater tuning potential for higher performance setups.

User-Friendly & Fully Reversible

Installation is plug-and-play with OEM-style connectors and requires no splicing or permanent modifications. The unit is not VIN locked, allowing you to remove it at any time without detection and resell it later. It also includes a rugged CNC-machined billet aluminum enclosure for long-term protection.

Smooth, Safe, and Efficient

The JB4 retains factory smoothness and supports all BMW driving modes. Fuel economy remains unchanged during normal driving, while performance dramatically improves under load. Required fuel: 91 octane or higher for optimal gains.

Backed by Industry-Leading Support

Proudly made in the USA and supported by a 5-year warranty, the JB4 ensures long-term reliability, safety, and proven performance unmatched by non-integrated tuning modules.

  Vehicle Fitment — GEN 3 B48/B58 Only

This JB4 ONLY fits GEN3 B48/B58 engines.
It will not fit previous-generation B48/B58 due to different connectors.

BMW 2 Series

• 2023+ F44 228i xDrive Gran Coupe (B48 GEN3)

BMW 3 Series

• 2025+ G20/G21 M340i (B58 GEN3), including xDrive

• 2025+ G20/G21 330i, 330e, 320i (B48 GEN3), including xDrive

BMW 4 Series

• 2025+ G22/G23/G26 M440i (B58 GEN3), including Gran Coupe & xDrive

• 2025+ G22/G23/G26 420i & 430i (B48 GEN3), including Gran Coupe & xDrive

BMW 5 Series

• 2024+ G60/G61 540i (B58 GEN3), including xDrive

• 2024+ G60/G61 530i & 530e (B48 GEN3), including xDrive

BMW 7 Series

• 2023+ G70 740i (B58 GEN3)

BMW X Series

• 2023+ U11/U12 X1 28i & xDrive28i (B48 GEN3)

• 2025+ G45 X3 M50 xDrive (B58 GEN3)

• 2024+ G05 X5 M40i & xDrive40i (B58 GEN3)

• 2024+ G06 X6 xDrive40i (B58 GEN3)

• 2022+ G07 X7 xDrive40i (B58 GEN3)

Important Fuel Requirement

• 91 octane or higher required for performance maps.