The BMW Z4 2.5i 211hp (E85 - 2003 - 2008) produces 211bhp and 250Nm in standard form. Our Stage 1 ECU tuning file raises output to 235bhp and 270Nm, a gain of 24bhp and 20Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.