JB4 for Mercedes-AMG 2.0T M139l Mild / Plug-in Hybrid

Tuning the Mercedes-AMG M139l

JB4 connects to two engine plugs, adjusts boost and rescales timing and fueling alongside the factory ECU. Burger lists up to 50 whp for the C43 and up to 100 whp for the C63 on pump gas; these are manufacturer maximums, and actual results vary with fuel, model and test conditions. Installation is removable and does not require an ECU flash.

Control and data

The JB4PRO adapter and free app support map switching, firmware updates and log analysis. CANbus adds engine data for monitoring. Burger specifies 91 octane or higher for gains; match the map to the fuel used.

Fitment

For Mercedes-AMG 2.0L Turbo M139l: C43 Sedan 2023+, GLC 43 SUV 2024+, GLC 43 Coupe 2026+, SL 43 and GT 43 2025+, C63 SE Performance Sedan 2024+, and GLC 63 S E Performance SUV/Coupe 2025+, as listed by Burger. Confirm body, year and version.