The BMW Z4 M40i has always been more than just a pretty face. With its classic roadster proportions, a silky inline-six under the hood, and rear-wheel-drive dynamics, it offers one of the purest open-air driving experiences in the BMW lineup. But for those who crave even more excitement, Swiss tuning firm dAHLer Competition Line has something special: the “DCL dAHLer Competition Line” upgrade—a full-blown transformation of the G29 Z4 M40i that brings more power, sharper dynamics, and unmistakable style.
Power Now Up To 455 HP
In stock form, the European-spec BMW Z4 M40i already packs a punch. Its 3.0-liter B58 inline-six engine delivers 340 horsepower and 500 Nm of torque, promising strong acceleration and that signature BMW six-cylinder smoothness. But dAHLer’s upgrades rewrite the spec sheet entirely.
Three performance stages are available, all with full EU and Swiss homologation and compliant with Euro 6d-Temp emissions standards:
- Stage 1: 408 hp and 610 Nm
- Stage 2: 430 hp and 630 Nm
- Stage 3: 455 hp and 650 Nm
Beyond the numbers, there’s more freedom too: cars built before June 2020 get their top-speed limiter removed in Stages 1 and 2, while Stage 3 eliminates the Vmax restriction on all production years. That means the Z4 M40i can finally stretch its legs to its full potential.
Breathing Easier, Sounding Meaner
To complement the power increases, dAHLer offers a suite of supporting hardware upgrades. A high-performance sports air filter and optional carbon fiber intake help the B58 breathe more freely. At the rear, a custom stainless steel exhaust system “built by dAHLer” offers twin ceramic-coated tips—either 90 mm or 100 mm in diameter—and available bi-valve control, allowing the exhaust note to be tailored to the driver’s mood.
Lower, Sharper, Faster
Performance isn’t just about horsepower so this Competition Line package also includes tailored suspension upgrades. The simplest option includes lowering springs, dropping the ride height by 25 mm at the front and 20 mm at the rear for a more planted stance. For those seeking full control, an optional performance coilover suspension allows both ride height and damping to be fine-tuned.
Wheels That Complete the Picture
Visually, the dAHLer Z4 M40i makes a powerful first impression. The tuner’s forged alloy wheels—particularly the dynamic CDC2 design—are tailored to BMW M cars and the Z4’s aggressive aesthetic. The CDC1 wheels are also available in forged or cast forms, with the cast variant offering the same 21-inch fitment for an even bolder look. Buyers can opt for:
- 20-inch setup: 9×20 (front) / 10×20 (rear)
- 21-inch setup: 9.5×21 (front) / 10.5×21 (rear)
To round out the transformation, dAHLer adds a suite of motorsport-inspired visual touches—each crafted in lightweight carbon fiber. There is a front spoiler lip, M-style mirror caps, and rear decklid spoiler. Each piece can be left in natural carbon finish or painted to match the body color for a fully integrated appearance.
