BMW Z4 ECU Remapping & Engine Tuning

Which Z4 engines gain the most?

The first-generation E85/E86 range gains between 7% and 9% across every engine we list. The 3.0si goes from 265 to 287 bhp (+8%) and the 2.0 four-cylinder from 148 to 162 bhp (+9%). The N46 2.0 and the N52 2.5 and 3.0 used in the later cars are all naturally aspirated, and their gains sit within two percentage points of each other.

The E89 shows the difference turbocharging makes inside a single generation. The sDrive30i kept the naturally aspirated N52 3.0 six and goes from 255 to 270 bhp (+5%). The sDrive35i has the same capacity but uses the twin-turbo N54, and goes from 302 to 350 bhp (+15%), with torque rising from 400 to 476 Nm.

The E89’s turbocharged 2.0 four-cylinders gain the most in percentage terms. The 181 bhp sDrive20i goes to 253 bhp (+39%), with torque rising from 270 to 342 Nm, and the N20-engined sDrive18i, the lowest-output E89, makes the largest increase in our Z4 figures.

The third-generation G29 uses only turbocharged engines, the B48 2.0 four in the sDrive20i and the B58 3.0 six in the M40i. Our figures for both are still in development.

Z4 generations we cover

E85/E86 (2002–2008). The E85 roadster was joined by the E86 coupé, built from 2006 to 2008. Until 2005 the range used M54 straight-sixes in the 2.2i, 2.5i and 3.0i; from 2006 the N52 2.5 and 3.0 sixes took over. The N46-powered 2.0i (2005–2008) was sold only in Europe. The Z4 M is the only Z4 with the S54B32 3.2 six.

E89 (2009–2016). The second generation introduced a retractable hard top and was built from February 2009 to August 2016. The sDrive35is used an upgraded N54 and came only with a seven-speed dual-clutch gearbox.

G29 (2018–2026). The third generation has a soft top. It is built in Austria and shares its platform with the Toyota Supra.

Last updated 19 October 2026