Brawny power, spontaneous response and high revs – and all underscored by voluminous, sonorous music. The V8 in the RS 5 Coupé conveys the skin-tingling feeling of power and emotion. Displacing 4,163 cc, the 4.2 FSI delivers impressive torque and just like a race engine is right at home even at high revs. It puts out 331 kW (450 hp) at 8,250 rpm, and the peak torque of 430 Nm (317.15 lb-ft) is available between 4,000 and 6,000 rpm. The rev limiter kicks in at 8,500 rpm.

The specific output of the normally aspirated eight-cylinder is 108.1 hp per liter of displacement. Each hp only has to move 3.83 kilograms (8.44 lb) – the RS 5 Coupé weighs just 1,725 kilograms (3,803 lb). The 4.2 FSI catapults the two-door model from a standing start to 100 km/h (62.14 mph) in 4.6 seconds; 200 km/h (124.27 mph) is reached after another 10.9 seconds. Top speed is an electronically governed 250 km/h (155.34 mph); Audi will raise this to 280 km/h (173.98 mph) at the customer’s request.

Efficiency and dynamics are inextricably linked at Audi. The ultra-powerful eight- cylinder engine averages 10.8 liters of fuel per 100 kilometers (21.78 US mpg) – far less than its main competitors. This figure is due in part to the technologies from Audi’s modular efficiency platform.

The cylinder barrels and the chain drive have been optimized to minimize friction, the oil pump operates on demand, and a recuperation system recovers energy during coasting and braking. The electricity is stored temporarily in the battery; it is used during the next acceleration phase to reduce the load on the generator and thus on the engine.

The high-revving, normally aspirated V8, whose cylinder head covers are painted red, is built by hand at the plant in Györ, Hungary, and has much in common with the V10 from the R8 high-performance sports car. Its classic 90 degree cylinder angle results in a low center of gravity. The two opposing banks are offset by 18.5 millimeters (0.73 in). The bore measures 84.5 millimeters (3.33 in) and the stroke 92.8 millimeters (3.65 in).

The V8 weighs just 216 kilograms (476.2 lb). Its crankcase is manufactured using the low-pressure die casting method, which ensures particular homogeneity. The aluminum-silicon alloy combines low weight with high strength. Its high silicon content makes the cylinder barrels extremely durable. The forged crankshaft, the forged steel connecting rods and the pistons forged from a high-strength aluminum alloy are all also extremely lightweight, yet strong.

Also on Blogsteady