Power gains of up to 130whp on a stock vehicle without the risks of flashing!

The JB4 is the most advanced and highly featured tuning system available for your B58 GEN3 powered vehicle. Power gains are up to 100whp to the wheels (125hp crank) on a completely stock car on 93 octane, and even higher with ethanol fuel mixed in!

This new JB4 BMW tuner is specifically designed for the latest B58 variant and is capable of processing the new ultra fast SENT digital sensor signals in real time with zero latency. The JB4 features a simple plug & play installation harness for easy installation & removal and includes many features not found with any other tune. Including on the fly in-app map switching between factory and various performance maps, boost limiting by gear for improved traction in lower gears, progressive water/methanol support, built-in data logging, built-in code reading, and much more. Other more expensive tuners may claim to equal the JB4’s technology but upon closer examination lack most if not all of the JB4’s features.

Remember the JB4 does not require any additional modifications or previous stages. Simply install the JB4 as your first and only modification and enjoy an entirely new fast and smooth racing experience. The JB4 also does not require any user setup or customization, but for those who are interested in logging, adding new features as we post them, etc, we suggest the Bluetooth mobile phone adapter.

Wirelessly connect the JB4 BMW tuner to your Bluetooth 4.0 compatible iOS and Android device via the JB4 Mobile connect kit or to your Windows laptop with the BMS data cable. Both options allow 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. A separate JB4 Mobile app purchase is also required.

Vehicle Fitment(GEN3 B58)

This only fits the exact vehicles below. Does not plug into previous years B48/B58 engines due to different connectors on the newer B48/B58 engines. Click here for previous generationB58 engines.

2 Series
2023+F44 B48 GEN3 BMW228i xDrive Gran Coupe

BMW 3 Series
2025+ G20 G21 B58GEN3BMW M340iincluding xDrive

BMW 4 Series
2025+ G22 G23 G26 B58 GEN3BMW M440iincludingGran Coupe and xDrive

5 Series
2024+G60 G61 B58 GEN3 BMW 540i including xDrive
2024+G60 G61 B48 GEN3 BMW530i, 530eincluding xDrive

7 Series
2023+ B58 GEN3 G70 BMW 740i

X Series
2023+U11 U12B48GEN3BMWX1 28i and xDrive28i
2025+ G45B58 GEN3 X3 M50 xDrive
2024+G05 B58GEN3BMWX5 M40i and xDrive40i
2024+ G06B58 GEN3X6 xDrive40i
2022+G07 B58GEN3BMWX7 xDrive40i