Hoping to satisfy the performance hunger of BMW fans that can't wait for the new M5 to arrive, AC Schnitzer has done some significant tinkering on the 550i.
The tuning company's theme at the Geneva Motor Show is "efficient performance" and fitting with that the new AC Schnitzer ACS5 Sport S claims to offer significantly more power than the 550i that it's based on without any fuel consumption penalties.
The company has not yet released details about what was done to the 550i's 4.4-litre force-fed V8 motor, but it has released output figures of 397kW and 750Nm, up from 300kW and 600Nm.
With the speed limiter also removed, the top speed is now 320km while the claimed 0-100 sprint time falls from 5.0 seconds to 4.5 seconds.
AC Schnitzer is also withholding information on its chassis mods, until the Geneva unveiling, but has disclosed that the Sport S has a limited slip differential and that "the driving behaviour of the new saloon is worthy of a thoroughbred sports car."