The Audi S5 TDI

The S TDI models in the A5 family are endurance athletes. For the first time, the Audi S5 Sportback (combined fuel consumption in l/100 km: 6.2 – 6.1*; combined CO₂ emissions in g/km: 162 – 160*) and S5 Coupé (combined fuel consumption in l/100 km: 6.2 – 6.1*; combined CO₂ emissions in g/km: 161 – 160*) have a V6 diesel engine under the hood. The 3.0 TDI produces 255 kW (347 hp) of power and up to 700 Nm (516.3 lb-ft) of torque between 2,500 and 3,100 rpm. A mild hybrid system with a belt alternator starter (BAS) increases efficiency, while the electric powered compressor (EPC) ensures powerful off-the-line performance. This synergy of power, torque, spontaneity, efficiency and range is unique in the segment.

The 3.0 TDI: 700 Nm (516.3 lb-ft) of torque

The 3.0 TDI, the most powerful unit in the Audi V6 diesel lineup, produces 255 kW (347 hp) and delivers its maximum torque of 700 Nm (516.3 lb-ft) between 2,500 and 3,100 rpm. The V6 diesel engine accelerates the S5 Coupé TDI and the S5 Sportback from 0 to 100 km/h (62.1 mph) in 4.8 and 4.9 seconds, respectively. Top speed is electronically governed at
250 km/h (155.3 mph).

The three-liter diesel, which operates with very high ignition pressures of up to 205 bar, is a high-tech engine. Its common rail system injects fuel at a pressure of up to 2,500 bar for clean, precise combustion. Crankshaft, pistons, connecting rods and oil management are configured for the stringent demands. Sophisticated measures in the crankshaft and camshaft drive reduce friction. The oil cooler, the EPC, the BAS and the compressor case of the turbocharger are integrated into the coolant flow as needed.

The larger turbo generates up to 2.4 relative boost pressure, and its variable turbine geometry (VTG) is optimized for low-loss flow. The external low-pressure exhaust gas recirculation (EGR) system draws off the exhaust gas downstream of the particulate filter so that the full mass flow can power the turbocharger, significantly increasing its effectiveness. An oxidation catalyst, a diesel particulate filter with an SCR coating and a downstream ammonia slip catalyst scrub the exhaust of pollutants. The S TDI models are significantly below the limits of the Euro 6d-temp emissions standard.

EPC and MHEV: high-tech systems in the 48-volt main electrical system

The electric powered compressor and the mild hybrid system with which the 3.0 TDI works together are integrated into the standard 48-volt main electrical system. A lithium-ion battery with an energy capacity of 0.5 kWh installed under the luggage compartment floor serves as the energy center. A DC/DC converter connects the 12-volt electrical subsystem.

The electric powered compressor is mounted close to the engine in a bypass downstream of the intercooler. If the driver demands a lot of power but the energy available in the exhaust flow is low, the throttle valve closes the direct air pathway so that the intake air now flows into the EPC, where it is compressed again. A compact electric motor with an output of up to 7 kW spins the EPC’s compressor wheel up to a maximum of 70,000 rpm in less than 250 milliseconds. Thanks to the support of the EPC, the power of the 3.0 TDI is available immediately when the driver needs it, whether starting off the line, accelerating at low rpm or changing loads. Off the line, the S TDI models quickly jump out to a lead of several meters over comparable vehicles.

The mild hybrid system in the S TDI models has to potential to reduce customer fuel consumption by as much as 0.4 liters per 100 kilometers. This is even more than with the MHEV system in A5 models with a four-cylinder engine, which is a 12-volt system. Connected to the crankshaft via a Poly-V belt, the belt alternator starter (BAS) is mounted on the end face of the engine. When the driver lifts off the accelerator, it can recover up 4 kW of power (8 kW during light braking), which it sends as electricity to the 48-volt storage unit. The BAS interacts closely with the TDI engine, which in many situations can be operated more closely to its ideal load point as a result. This improves efficiency. If the driver lifts off the accelerator at a speed between 55 and 160 km/h (34.2 and 99.4 mph), the car can coast for up to 40 seconds with the engine shut off. The lithium-ion battery maintains the power supply. Based on information from the navigation system and the onboard sensors, the drive management system decides anew in every situation whether coasting, idling or recuperation is more efficient. As soon as the driver presses the accelerator pedal again after a coasting phase or a stop, the BAS restarts the TDI very smoothly and very quickly. Start-stop operation begins at a speed of 22 km/h (13.7 mph). When stopped, the engine restarts when the car in front starts to move, even if the brake is depressed.

* Figures depend on the tires/wheels used

Audi offers the S5 Coupé and the S5 Sportback with the 3.0-liter TFSI in markets outside Europe. The turbocharged gasoline direct injection engine has an output of 260 kW (354 hp) and produces a hefty torque of 500 Nm (368.8 lb-ft) from 1,370 to 4,500 rpm. The V6 engine propels the S5 Coupé TFSI from 0 to 100 km/h (62.1 mph) in 4.7 seconds and up to an electronically governed top speed of 250 km/h (155.3 mph). The standard sprint takes two tenths of a second longer in the S5 Sportback TFSI.

The eight-speed tiptronic, which in the S models transfers the engine’s power, interacts perfectly with the MHEV technology thanks to an additional oil pump with an electric drive unit. This is responsible for lubrication when the car is coasting with the engine deactivated and the mechanical pump is stopped. It also generates the oil pressure necessary to engage the gear needed when the engine is restarted. In those phases in which the car is rolling with the engine idling, a clutch in the central transmission decouples the gear sets. This, too, contributes to efficiency.

As with all Audi S models, quattro drive – in this case with a mechanical center differential – is standard. It is supplemented with wheel-selective torque control. Audi offers the sport differential as an option. The sport differential actively distributes the torque between the rear wheels during dynamic cornering. It literally pushes the car into the curve, nipping understeer in the bud. During sporty cornering, the sport differential ensures that steering commands are carried out precisely and stably, providing for outstanding agility.

The electronic chassis platform (ECP) controls the sport differential quickly and precisely. This central controller computes the ideal distribution of torque with respect to dynamic driving for the sport differential. The sport differential is integrated into the Audi drive select dynamic handling system. This allows the driver to experience a range of chassis settings in the vehicle.

Dynamics with high tech: the suspension technologies

The suspension technologies play large role in the dynamic character of the S5 models. The taut S sport suspension is standard equipment and complemented with S-specific damper control and dynamic steering. 18-inch wheels with 245/40 tires are standard. 19- and 20-inch wheels are available as options, the latter from Audi Sport. The ventilated brake discs on the front axle measure 375 millimeters (14.8 in) in diameter (350 millimeters (13.8 in) with the TFSI). The calipers (optionally available painted red rather than black) each have six pistons. Using the Audi drive select dynamic handling system, drivers can specify the mode in which key drive and suspension systems should operate. They can also activate a sound actuator here, which gives the V6 diesel a sonorous sound.

The design: sporty expression

The exterior of the S5 TDI models follows the new design language of the model family while setting individual accents. Thick clasps structure the large, honeycomb-filled air inlets; light glossy elements accentuate the Singleframe’s grille. Viewed from the side, the silver exterior mirror housings are particularly eye-catching. Other S features include the subtle spoiler on the luggage compartment hatch and the four chrome-tipped tailpipes. The diffuser is finished in Dark Chrome matt and is enclosed on three sides by a chrome clasp. It includes a honeycomb grille, and ribs structure the lower zone. Paint finishes in Daytona gray, quantum gray and turbo blue are reserved for the S models (as well as the S line).

The interior of the S5 TDI models is bathed in cool black. The sport seats with S embossing are standard; S sport seats with integrated head restraints and a rhombus pattern are optionally available. The upholstery – optionally with contrasting stitching – is available in a leather/Alcantara combination, leather/artificial leather mono pur or in fine Nappa leather, either in red, rotor gray or magma red. The pedal caps and the footrest are stainless steel, the inlays matt brushed aluminum or optionally carbon Atlas.

The optional Audi virtual cockpit plus presents all displays in a specific look. The driver can switch between sport mode and S mode, where the tachometer takes center stage. If they run out the gears with the tiptronic in manual mode, a shift light indicates to the driver when to change gears. There are displays for the engine oil temperature, the boost pressure of the turbocharger and lap times at a racetrack.

From 66,500 euros: launch early 2020

The Audi S5 TDI models come with a comprehensive range of comfort and safety features, connectivity solutions and assist systems. The Audi S5 Sportback TDI and the Audi S5 Coupé TDI will arrive on the European market in early 2020. In Germany, they share a base price of 66,500 euros. 

* Fuel/power consumption and CO₂ emission figures given in ranges depend on the tires/wheels used as well as the selected equipment

All terms in blue in the text are explained in detail in the technology lexicon at www.audi-mediacenter.com/en/technology-lexicon.

The specified equipment, data and prices relate to the model range on offer in Germany. Subject to changes and errors. Figures on the fuel consumption and the CO₂-emissions (found from page 2 onwards) vary in case of given ranges depending on the used combination of wheels/tires.