Audi TT RS, 2010
The Audi TT RS has a turbocharged 2.5-liter engine with direct gasoline injection; it produces 250 kW (340 bhp) and 450 Nm (331.90 lb.-ft.) of torque. The blazing five-cylinder engine enables the Audi TT RS to perform extraordinary feats. In conjunction with quattro permanent all-wheel drive and a high-performance chassis, the engine makes the compact Audi TT RS a top-notch sports car - available as a coupé or roadster.
Sporty five-cylinder gasoline engines have a long legacy at Audi. The most famous is arguably the turbocharged 2.1-liter engine in the Audi quattro. The first version, which was launched in 1980, offered an impressive 147 kW (200 bhp). And the Audi Sport quattro from 1984, directly inspired by motorsport, delivered a whopping 225 kW (306 bhp). For 25 years, turbochargers and quattro have been a dynamic formula for success.
Audi has resumed using this recipe. Designed from scratch, the five-cylinder engine combines a turbocharger with FSI direct gasoline injection to elevate the Audi TT RS to a high-performance sports car. The TFSI delivers 250 kW (340 bhp) from a displacement of 2,480 cc (151.34 cu in): a specific output of 100.8 kW (137.1 bhp) per liter.
The power-to-weight ratio is also outstanding. In the case of the Coupé, which weighs in at a mere 1,450 kilograms (3,196.70 pounds), the power-to-weight ratio is just 4.3 kilograms per bhp. The Audi TT RS Roadster has a weight of 1,510 kilograms (3,328.98 pounds) and a power-to-weight ratio of 4.4 kilograms per bhp - thanks to its extremely lightweight and largely aluminum body constructed as per the Audi Space Frame principle.
The Audi TT RS Coupé rockets from 0 to 100 km/h (0 to 62.14 mph) in 4.6 seconds; the Audi TT RS Roadster needs just a tenth of a second longer. The limited top speed of 250 km/h (155.34 mph) is merely the official figure for both versions; as an option, Audi can increase it to 280 km/h (173.98 mph).
Compact and Lightweight: The Five-cylinder TFSI
The ultra-powerful five-cylinder engine is extremely fuel-efficient, requiring an average of just 9.2 liters/100 km [25.57 mpg] as regards the Coupé (Roadster: 9.5 l/100 km [24.76 mpg]). Switchable flaps in the intake manifold mix the incoming air in a calculated configuration. Injected at a pressure as high as 120 bar by the common-rail system, the gasoline swirls intensely in the combustion chamber - which in turn cools the walls. This subsequently facilitates a compression ratio of 10.0:1, which is very high for a turbocharged engine. Both of the adjustable camshafts, controlled via chains, also enhance charging efficiency with respect to the air-fuel mixture.
The large turbocharger generates up to 1.2 bar of boost pressure. The intercooler, fed air ideally by the lower segment of the single frame radiator grille, reduces the temperature of compressed air by over 80 percent at full load.