Audi S4: With turbo and 354 hp from 59,300 euros

B ebefore Audi crowns the A4 series with an RS4 model, the S4 can serve the sporty, ambitious customers. In the new generation of the A4 (B9), both sports models will be launched much earlier in the model cycle of the series than before. Nevertheless: the fans have to wait until 2017 for the RS4. The S4 will roll out to customers in spring 2016 as a sedan and avant. The prices for the hot sedan start at 59,300 euros, the Audi S4 Avant is available from 61,150 euros.

Audi

The new S4 relies on turbo technology instead of a compressor.

Audi S4 (2016) optically close to S -Line

Visually, the 354 HP bolide remains quite discreet. Little distinguishes it from a new A4 with an S-Line package: Sure, the exterior mirror housings have an aluminum look, a spoiler lip sits on the trunk lid, the rear apron is slightly different, above all the diffuser has clearly recognizable webs underneath and two tailpipes protrude on both sides double-flow exhaust system, the diameter of which comes closer to a half-full than an empty clo-paper roll. And the radiator grille has double chrome strips instead of the extensive chrome clips on the S-Line model next to it. But that should have been it. Inside, the driver looks at the digital display, which is standard on the S4, which, like the R8, can also be configured to be sporty - then a very large rev counter is emblazoned in the middle.

Also recognizable: the chassis of the S4 models sets it The body is 23 mm lower and there are 19-inch wheels at the ends of the axles on request (standard: 18-inch rims with 245/40 tires). Optionally there are also adaptive dampers, dynamic steering and a limited slip differential for the rear axle.

Audi S4 now with turbo instead of compressor

The most exciting thing is of course under the hood: The new one, three again literlarge V6, is no longer forced ventilation by the inefficient compressor, but by a mono turbocharger. V6 with only one turbo? This is indeed possible - ideally if the intake side of the cylinder banks is not in the V of the engine, as has been the case for many years, but the (hot) exhaust side. Although this is a thermal challenge, it allows the bends to be routed in such a way that all pipes run to the same turbine over short distances. Or, alternatively, the sorting of the exhaust gas flows from the individual cylinders so that they do not reduce each other's pressure. BMW was the first to implement this with a so-called twin scroll charger in the V8 of the X6 M or the current M5.

This allows the performance to be scaled up nicely. It is quite conceivable that a similar technology will then be used in the RS4 in order to surpass the 450 hp of the predecessor with high-speed V8 - unless Audi has the electric charger ready for series production in 2017. Either way: A new turbo RS4 should easily have the potential to make the legendary biturbo V6 of the B5 series forgotten - even the 500 PS brand does not have to remain an insurmountable barrier.

Audi S4 - pressure meets traction

When it comes to torque, the 500 is certainly not an issue. The S4 already manages 500 Nm (60 more than the predecessor and 70 (!) More than the RS4 with V8). And just above idle speed (from 1300 rpm). All-wheel drive really makes sense! The sedan, which weighs 1,630 kilograms (Avant 1,675 kg), accelerates correspondingly quickly: the new S4 should jump to 100 km /h in 4.7 seconds (predecessor: 5.0 s). As usual, the top speed is limited to 250 km /h.

The fact that the output of the direct injection engine in the S4 only rose moderately (354 instead of 333 hp) shows more of the potential that the turbo engine still has: the compressor in the old S4, it consumed 20 kW of drive power at maximum speed. That's why the new engine concept is also more economical: Audi specifies the standard consumption of 7.4 liters per 100 kilometers, while the predecessor's consumption was 7.7 liters even in the less demanding measurement cycle.

Audi S4 in future with ZF 8-speed automatic

The technology is also changing with the transmission: in the future, the eight-speed automatic will shift gears. Sporty enough for an S model, according to Audi; Thanks to the start-stop technology, the automatic converters need a lot of pressure in the shift hydraulics so that the shift times are nice and short. For the RS4, however, one could certainly imagine a sportier circuit, according to an Audi spokesman. There is a dual clutch transmission that works fine in the R8, for example.

Conclusion:

With the new S4, Audi has eliminated the birth defect of the compressor and at the same time switched the RS4 back to turbo technology . Even if the high-revving V8 is a shame - the high-torque turbo technology goes better with the quattro drive anyway. And for the RS4 it should be particularly refined - either withmore, shared or electric chargers. The downside: the former variety of drive systems in the sports sedan segment is a thing of the past. Turbo rules, whether at Alpina, BMW, Mercedes or Audi. Only Jaguar (still) stays with the compressor.