Audi switches to diesel in the new Audi S6 and S7 Sportback

The new Audi S6 and Audi S7 Sportback debut a powerful 350 CV V6 TDI with Mild-Hybrid technology, which gives them the ECO label.

Amid so much controversy over diesel and petrol engines, Audi is clear on the matter: diesel still has a lot of potential. And although outside Europe the new Audi S6 and Audi S7 Sportback will keep the V6 TFSI engine, in the European market these S family versions debut a new 3-litre V6 TDI engine.

Double supercharging: turbo and electric compressor

The heart of these new S family versions is the 3-litre V6 TDI, which delivers a maximum power of 350 CV, with a peak torque of 700 Nm between 2,500 and 3,100 rpm. As always in Audi’s “S” models, permanent quattro all-wheel drive is fitted. The automatic gearbox here is an eight-speed tiptronic.

The main feature of this engine is that Audi repeats the formula it first debuted on the V8 of the Audi SQ7 for its supercharging system. We have already seen it announced, not least, in the new Audi SQ5.

The secret of its performance lies in the combination of a conventional turbocharger driven by the exhaust gases with an electric compressor called EPC. The two are placed in tandem and work together.

The EPC runs on the main 48-volt electrical system. It compresses the intake air when the engine is under a load that does not generate enough exhaust gas flow for the turbocharger to do so. The result is greater thrust from a lower rev range, and the elimination of the characteristic response lag of some turbocharged engines.

With this engine, the Audi S6 accelerates from 0 to 100 km/h in 5 seconds; and the S6 Avant and S7 Sportback need one tenth of a second more. In all cases the top speed is electronically limited to 250 km/h. As for consumption, on the WLTP cycle, the S6 is homologated at 7.8 l/100 km, and from 7.9 l/100 km for the S6 Avant and S7 Sportback.

Mild Hybrid technology and ECO label

In addition to this new supercharging system, and like the rest of the engines in the Audi A6 and A7 Sportback ranges, these new S versions also include Mild Hybrid (MHEV) mild-hybrid technology.

The electric motor that acts as alternator and starter, connected to the crankshaft by a belt, can recover up to 8 kW of electrical energy during deceleration phases. This energy is stored in a 10 Ah lithium battery located in the boot.

Thanks to this technology, which according to Audi allows fuel savings in real-world use of up to 0.4 l/100 km, the new Audi S6 and Audi S7 Sportback qualify for the DGT ECO label under current regulations.

Four-wheel drive and four-wheel steering

Another important technical novelty in the new Audi S6 and S7 Sportback is the arrival of four-wheel dynamic steering, offered as an option to the standard progressive steering, with specific “S” settings.

With four-wheel steering, the front axle has dynamic steering independent of the rear, which can change the steering ratio depending on the angle of the steering wheel.

For its part, the rear wheels can turn up to 5 degrees in the opposite direction to the front wheels at low speed (up to 60 km/h) to improve agility and reduce the turning circle in manoeuvres. And above that speed they turn up to 2 degrees in the same direction as the front wheels, with positive effects on stability and on agility when changing lanes.

Now, the sporty S-specific suspension on the S6 and S7 includes, as standard, controlled damping. It has different ride height settings, and at speeds above 120 km/h the body lowers by 10 mm. Optionally, the sport rear differential on the rear axle can also be fitted.

And also as an option, for the most demanding, the standard brakes with six-piston calipers and 400 mm steel discs on the front axle (350 mm on the rear axle) can be replaced with ceramic brakes. In this case, the weight saving reaches 9 kg compared with steel units. The standard wheels are 20 inches, with 255/40 tyres.

The new Audi S6 and S7 Sportback will be available on the Spanish market from next May.

Audi S7 image gallery

Audi S6 and S6 Avant image gallery