G80 Tuning

No M3 has been argued about like the G80 — the grille, the weight, the auto-only Competition. Put the S58 on a dyno, though, and the argument quiets down: whatever you make of the styling, it's the most capable engine BMW has put in an M3.

The reason is the block. The S58 is a closed-deck development of the B58 — the same family as the Supra — reinforced for boost, and it ran in the X3 M and X4 M before it reached the M3, so it arrived proven. The Competition makes 503 hp and 479 lb-ft, and that's the conservative starting point: tuners have documented 600–700+ wheel horsepower on the stock turbos with E85 and supporting fuel — figures that used to mean a built engine. The factory turbos still pull flat near redline, so they aren't the limit yet.

Which trim you own shapes the build. The six-speed manual is rear-drive only and lower-output; the auto brings xDrive and Competition power. "Which gearbox" is really "which car."

The honest part, because you'll live with it: the S58 is direct-injected, so the intake valves carbon up over time — plan a walnut-blast as maintenance, not a fault. Some cars use oil; keep an eye on the level. Early 2021 cars had iDrive glitches, mostly cured in software. Buying used, confirm the 2021 brake recall was closed. And unlike the S55 it followed (see the F80's crank hub), the bottom end is the part nobody worries about.

Get the calibration right and the G80 does the rare thing: meaningfully quicker, still daily-drivable, on the hardware it came with.