VIDEO: AC Schnitzer's Diesel-Powered BMW Z4 and 540HP 5-Series

The new BMW Z4-based 99d roadster and the BMW 550i-based ACS5 sports saloon will hog the limelight on AC Schnitzer's stand at this week's 2011 Geneva Motor Show. Both models were developed to offer performance without compromising on fuel efficiency and CO2 emissions. The Z4 99d comes with a 190HP 2.0-liter turbo diesel engine, while the ACS5 features a 4.4-liter turbocharged V8 gasoline unit