Engines in the A5 family – three gasoline engines and four TDIs – raise the bar in terms of sportiness and efficiency. All these engines embody Audi’s downsizing philosophy. These turbocharged direct-injection units provide plenty of torque; even the entry-level four-cylinder engine delivers 320 Nm (236.02 lb-ft) of torque. The recuperation system and the start-stop system are standard in every version – no other manufacturer is so resolute. Across this model line, CO2 emissions have been reduced by 11 percent on average – even though several engines have grown more powerful.
Even the 1.8 TFSI, which has the lowest displacement, demonstrates Audi’s engine expertise. Audi specialists have thoroughly enhanced the four-cylinder unit and created new solutions regarding numerous aspects of engineering. This hard work pays off in the form of robust performance and great fuel efficiency.
The high-end four-cylinder engine attains its maximum torque of 320 Nm (236.02 lb-ft) at just 1,400 rpm and steadily transmits it as high as 3,700 rpm. At just 3,800 rpm, it reaches its maximum output of 125 kW (170 hp). The 1.8 TFSI propels the Audi A5 Coupé from 0 to 100 km/h (62.14 mph) in 7.9 seconds en route to a top speed of 230 km/h (142.92 mph). It nevertheless averages just 5.7 liters of fuel per 100 km (41.27 US mpg), which equates to 134 grams of CO2 per km (215.65 g/mile) – a new best figure in its segment. Compared with the predecessor engine generating 118 kW (160 hp), fuel consumption has dropped by 18 percent.
A central innovation in the 1.8 TFSI is the addition of indirect fuel injection. At partial throttle, it aids the FSI gasoline direct injection to further boost fuel efficiency and reduce particulate emissions to levels stipulated by the EU’s upcoming Euro 6 standard. FSI fuel injection is active when the vehicle starts up or is operating under high loads. The valve gear has been granted new degrees of freedom. The Audi valvelift system, which varies the lift of the valves as needed, acts on the exhaust valves; the camshafts are adjustable.
Innovative thermal management constitutes yet another new feature: two rotary slide valves regulate the flow of coolant. These valves ensure that the engine oil heats up to its operating temperature soon after the vehicle is started; they also maintain the water temperature, as per a given driving situation, between 85 and 107 degrees Celsius (185.0° F and 224.6° F). As a result – regardless of load or engine speed – the valves always strike the perfect balance between minimal friction and high thermodynamic efficiency.
The exhaust manifold is integrated into the cylinder head, where it is bathed in water. This solution cools the exhaust gas. The turbocharger is also a new development. Its most important innovation is an electric wastegate actuator that adjusts the boost pressure particularly quickly and precisely. It also optimizes the engine’s responsiveness.
The weight of the 1.8 TFSI has been reduced from 135 to 131.5 kilograms (297.62 to 289.91 lb). Internal friction has also been significantly reduced by the use of an innovative coating on the piston skirts and by mounting the two balance shafts in roller bearings. The regulated oil pump requires little energy itself, and a high-precision electric system controls the oil-jet cooling for the piston heads.
Proven champion: The 2.0 TFSI
The 2.0 TFSI – declared Engine of the Year five times in a row, from 2005 through 2009 – is the mid-range gasoline engine in the A5 portfolio. Its highlights include adjustable intake camshafts, the Audi valvelift system at the exhaust end, two balance shafts, minimized internal friction, the new turbocharger and the regulated oil pump.
The 2.0 TFSI delivers 155 kW (211 hp) and generates 350 Nm (258.15 lb-ft) of torque between 1,500 and 4,200 rpm. It propels the A5 Coupé with S tronic and a quattro drivetrain from 0 to 100 km/h (62.14 mph) in 6.5 seconds; the vehicle’s top speed is 245 km/h (152.24 mph). With the optional multitronic, available before long, fuel consumption amounts to 6.4 l/100 km (36.75 US mpg), with CO2 emissions of 148 g/km (238.18 g/mile).
At some point in the not-too-distant future, Audi will roll out the A5’s most powerful gasoline engine: the supercharged 3.0 TFSI. Positioned in the cylinder banks’ 90-degree V, the supercharger is driven by the crankshaft via a belt. Two opposed pistons inside the supercharger rotate at over 20,000 rpm; the air gap between them is just a few thousandths of a millimeter. The compressor first compresses the intake air as high as 0.8 bar; two intercoolers then cool down the hot air.
The gas travel paths behind the supercharger are short so that torque is generated early and quickly. The compressor is behind the throttle valve, which boosts the former’s efficiency. An extensive array of measures makes the compressor less noisy; a balance shaft in the engine’s light-alloy crankcase enhances smooth running. Adjustable intake camshafts and tumble flaps in the intake ports optimize charging efficiency in the combustion chambers.
The high-revving, refined and sonorous 3.0 TFSI produces 200 kW (272 hp) and generates an impressive 400 Nm (295.02 lb-ft) of torque between 2,250 and 4,750 rpm. The A5 Coupé 3.0 TFSI requires just 5.8 seconds to cover zero to 100 km/h (62.14 mph) and has a governed top speed of 250 km/h (155.34 mph). It consumes 8.1 l/100 km of fuel (29.04 US mpg) and emits 190 grams of CO2 per kilometer (305.78 g/mile). A second version of the 3.0 TFSI, with 245 kW (333 hp), powers the S models.
Powerful and highly efficient: the TDI engines
TDI engines from Audi stand for modern and smart sportiness. They combine powerful performance, terrific torque, good fuel efficiency and driving refinement to create a harmonious overall impression.
Even the 2.0 TDI is a powerful engine, offered by Audi in two versions. In a version available before long only for the Sportback and Cabriolet, 105 kW (143 hp) of output is paired with 320 Nm (236.02 lb-ft) of torque between 1,750 and 2,500 rpm. The higher-output version features a number of optimized details and delivers 130 kW (177 hp) as well as 380 Nm (280.27 lb-ft) of torque between 1,750 and 2,500 rpm.
Special technical features of both four-cylinder diesel engines include low internal friction, a turbocharger with adjustable vanes, and a new centrifugal governor in a dual-mass flywheel. It requires little mass to compensate for a large share of vibrations caused by the engine. The vehicle runs even more smoothly at low engine speeds, which facilitates earlier upshifting and, consequently, better fuel efficiency.
The 2.0 TDI with 130 kW (177 hp) allows the manual-transmission A5 Coupé to accelerate from 0 to 100 km/h (62.14 mph) in 8.2 seconds and reach a top speed of 230 km/h (142.92 mph). On average, it consumes just 4.7 l/100 km (50.05 US mpg) and emits 122 grams of CO2 per kilometer (196.34 g/mile).
Powerful and refined: the V6 TDI
Three refined V6 diesel units, each with a displacement of 3.0 liters, round out the high-end lineup. Their key characteristics include a low weight just above 190 kilograms (419 lb), an energy-saving chain drive, low friction, a regulated oil pump and a truly elaborate thermal-management system. The crankcase and the cylinder heads have separate coolant circuits, which are interconnected via valves.
The 3.0 TDI with 150 kW (204 hp) is the most efficient V6 diesel in its class. Audi precisely optimized it for maximum fuel efficiency: from the camshafts’ control times through the turbocharger to the common-rail system providing injection pressure up to 2,000 bar. The 3.0 TDI produces 400 Nm (295.02 lb-ft) of torque between 1,250 and 3,500 rpm. It propels the A5 Coupé with multitronic from 0 to 100 km/h (62.14 mph) in 7.1 seconds en route to a top speed of 235 km/h (146.02 mph). It averages just 4.9 liters of fuel per 100 km (48.00 US mpg), with CO2 emissions of 129 g/km (207.61 g/mile).
In its most powerful configuration, the 3.0 TDI generates 180 kW (245 hp) as well as 500 Nm (368.78 lb-ft) of torque between 1,400 and 3,250 rpm. With this engine, the A5 Coupé with S tronic requires just 5.8 seconds to cover zero to 100 km/h (62.14 mph); its electronically governed top speed of 250 km/h (155.34 mph) is a mere formality. It sips just 5.7 l/100 km (41.27 US mpg) – thereby emitting only 149 grams of CO2 per kilometer (239.79 g/mile).
A “clean diesel” version of the top-of-the-line TDI to be rolled out before long will comply with the emission limits of the EU’s Euro 6 standard. Sensors in the combustion chambers, a common-rail system with injection pressure up to 2,000 bar, and a high-performance exhaust recirculating system lower emissions. A DeNox catalytic converter employs an additive to reduce residual nitrogen oxides. Key data for the A5 Coupé: zero to 100 km/h (62.14 mph) in 5.8 seconds; a top speed of 250 km/h (155.34 mph); average fuel consumption of 5.7 l/100 km (41.27 US mpg); 149 grams of CO2 per kilometer (239.79 g/mile).
The equipment and data specified in this document refer to the model range offered in Germany. Subject to change without notice; errors and omissions excepted.