G-Power skipped the full-blown M cars entirely and went straight for BMW's B58-powered lineup instead — the M240i, M340i, M440i and Z4 M40i. And the result is worth a second look: the new GP-480 package turns these cars into meaner versions of themselves. 480 hp, a 300 km/h top speed and an exhaust that can hit 100 dB — numbers that used to be reserved for the "senior" M badge.
Here's the twist: the B58 has long been considered one of BMW's best modern engines. It's a 3.0-liter turbocharged inline-six fitted to "non-M" models, but its durability and character have kept it firmly on enthusiasts' radar for years. G-Power simply tapped into that potential — without anyone having to buy an M3 or M4.
GP-480 isn't just a software flash. The package bundles proprietary software, an HJS downpipe, the G-Power DEEPTONE rear silencer with carbon tailpipes, reinforced charge pipes and an intercooler. The upgrade addresses several weak points of a boosted turbo engine at once: intake air temperature, exhaust flow capacity and boost stability — hitting exactly the spots where amateur upgrades usually stumble.
The package fits the BMW G42 M240i, G20/G21 M340i, G22/G23/G26 M440i and the G29 Z4 M40i roadster. For owners, the appeal is that the car stays closer to a daily-driver format: less aggression and expense than an M car, but performance edging into that territory. Factory B58 output usually sits in the mid-300-hp range, and this upgrade pushes the car to a point where the real limiting factor is no longer the engine, but the chassis, tires and brakes.
G-Power says the components can be ordered individually or as a full package. Installation takes place at the company's headquarters in Gachenbach, Bavaria, where the car is tuned on an in-house dyno, then inspected and certified. Crucially, the package is promised in road-legal, registrable form — not as a track-only kit.
G-Power hasn't announced pricing for the GP-480 yet. And that's exactly the detail that will decide a lot: if the package turns out to be significantly cheaper than stepping up to an M3 or M4, the B58 just gained another solid argument against the senior badge.
