AC Schnitzer (ACS) submits this little bit of outside the box thinking for your approval: what if someone swapped a torquey diesel motor into a Z4 sDrive 23i? What would that look like? And how capable would it be?
Wonder no more, friends; the noted tuner has done just that, plopping a built BMW N57S turbocharged 3.0-liter inline-6 diesel into the engine compartment of an E89. The mill reportedly makes 430 horsepower and a whopping 619.5 lb.-ft. of torque, and routed through a swapped 8-speed automatic gearbox with pedal sports shift and rear axle gear and limited slip differential from an E92 M3 can go 0 to 100 km/h (62mph) in 4.5 seconds.
ACS calls the engineering mash-up the BMW ACZ4 5 Concept, and the wonders don't stop at the engine bay. Curb weight is reduced some 120 pounds even with a heavier power plant, thanks in part to lightweight components like the 19-inch Type III forged alloy rims, lightweight exhaust silencer and CFC roof and boot lid.
The ACZ4 5 rides on a racing suspension, fully adjustable in both compression and rebound, and slows/stops via a lightweight high-performance braking system up front. Aero tweaks include carbon front spoiler and two-piece rear spoiler, while bits like the vented fenders and bonnet vents help to maximize engine efficiency. Cabin upgrades consist of aluminum pedals and footrest, velour floor mats, orange trim elements and carbon bucket seats embroidered with the ACZ4 5.0d logo.
The ACZ4 5.0d is a concept vehicle and not for sale - but if it was would fetch in the ballpark of $121,000 in its current form, according to ACS. As this project car was a product development exercise, however, AC Schnitzer will be offering the brakes, suspension, body, interior and wheel set as part of its mod package for the Z4.