JB4 Plug-and-Play Performance Tuner – Mercedes-Benz C300, E300, GLC300, & SLC300

The JB4 Performance Tuner is the most advanced plug-and-play tuning system available for the Mercedes-Benz M274 platform. It safely increases boost, optimizes timing and fueling, and delivers strong horsepower and torque gains while maintaining factory-smooth drivability.

Proven Power Gains

• Up to +40–60 WHP on C300 / GLC300 / GLE300 models
• Even higher results possible with supporting mods, race fuel, or E85 blends

Boost is safely increased by approximately 3–6 PSI, with timing and fueling intelligently managed for reliability.

True Plug & Play Installation

• Installs in minutes using easy-to-access connections on top of the engine
• No cutting, splicing, or permanent modifications
• Fully reversible and leaves no trace when removed
• Compatible with both AWD and RWD vehicles

Advanced CANbus Integration

Unlike basic piggyback devices, the JB4 uses full CANbus OBDII integration to monitor real-time engine data and make intelligent adjustments for smoother, safer performance.

• Fuel and spark control for high-power operation
• Better drivability than non-integrated chip tunes
• Optional BCM support for advanced boost control

Smartphone Control & Datalogging

• Change maps on the fly via iOS or Android
• View and log up to 40 engine parameters in real time
• Read and clear diagnostic fault codes
• Firmware updates and new maps available over the air

JB4 Mobile app sold separately. Bluetooth adapter required.

Exclusive JB4 Features

• Up to 8 preloaded tuning maps
• E85 / ethanol compatible maps
• User-adjustable boost-by-gear
• Valet mode with reduced power
• Exhaust flap control on supported vehicles

Exact M274 Compatibility

• C-Class: C300 (W205)
• E-Class: E300 (W213)
• GLC: GLC300 (X253)
• SLC: SLC300 (R172)

2019+ models use updated SENT pressure sensors and require the correct JB4 version. Please confirm your vehicle details when ordering.

Key Benefits

• Noticeably stronger acceleration and mid-range pull
• Fuel economy remains largely unchanged during normal driving
• 91+ octane recommended
• Not VIN-locked — transferable or resellable
• Rugged billet aluminum enclosure
• Made in the USA
• 5-Year Manufacturer Warranty

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