The latest addition to the Audi RS family is the 2014 Audi RS7 Sportback, capable of a top speed of 189 miles per hour thanks to a 4.0 TFSI engine putting out 560 horsepower and 553 lb-ft of torque. The vehicle made its debut earlier today at the Detroit Auto Show, displaying aggressive styling that hints at a 0 – 62 mph sprint time of just 3.9 seconds, and the aforementioned 189 top speed that comes with the purchase of the dynamic package plus. Even with the impressive performance abilities, Audi says the RS7 has 24 miles per gallon fuel efficiency, featuring a cylinder-on-demand system in which the V8 deactivates up to four cylinders by closing their valves. It then runs as a four cylinder engine until the driver accelerates strongly again, ultimately increasing efficiency. The 2014 Audi RS 7 is scheduled to arrive in U.S. showrooms this fall.