JB Diesel (JBD) Performance Tuner for Mercedes SLK 250, C250, E250, GLK 250 CDIInstantaneous increase in Power and Torque! Take your diesel powered SLK 250, C250, GLK250, and E250 to the next level with this simple plug and play tuner. Increases torque and power across the power band with the most noticeable increases coming at lower RPM and throttle positions where you really need them. In addition to adding power and torque, it reduces turbo lag and improves throttle response. Gains are up to 20 hp to the wheels and 40 torque