Now that the new A4 sedan and A4 Avant wagon are out in the open, attention turns to other variants of the small Audi like the sporty S4 and high-performance RS 4 as well as the A4 Allroad soft-roader.
are out in the open, attention turns to other variants of the small Audi like the sporty S4 and high-performance RS 4 as well as the A4 Allroad soft-roader. The next ones we’re scheduled to see will be the new S4 sedanand S4 Avant, which according to reports out of Germany will be unveiled together at the 2015 Frankfurt Auto Show. Prototypes have already been spotted in the wild, revealing most of the visual updates we can expect on the outside. But what’s yet to be confirmed is just what engine will be fitted under the hood.
It was previously thought that the new S4 would receive an uprated version of the supercharged 3.0-liter V-6 found in the outgoing model. However, Auto Zeitung (via World Car Fans ) is reporting that the new S4 will actually pack a turbocharged V-6, a slightly detuned version, in fact, of the engine destined for the new RS 4.
This engine will feature a twin-turbocharging system, with the smaller of the two turbos relying on an electric motor to spool up its compressor at low revs, helping to eliminate lag. Called an E-Turbo, the technology also allows the smaller turbo to continue to boost charge pressure when too little energy is left in the exhaust gas spinning the larger turbo in a conventional manner. This operating principle makes it possible to design the turbocharging system more specifically for high charge pressures and consequently for high engine power, with the E-Turbo assuring spontaneous response and powerful sprints throughout the rev range.
In the new S4, the engine is said to be spitting out around 350 peak horsepower, and in the RS 4 the same engine will be dialed up to deliver closer to 500 hp. The current S4 makes do with 333 hp from its supercharged V-6, while the current RS 4, which isn’t offered in the United States because of its exclusive wagon bodystyle, generates 450 hp from a naturally aspirated 4.2-liter V-8.
Audi has major plans for the E-Turbo, which is actually supplied by French firm Valeo. Some additional vehicles where we might see it include a new SQ7(also tipped for a Frankfurt Auto Show debut), new RS 5and possibly in a planned turbocharged version of the new R8 supercar. We should have more details soon as the Frankfurt Auto Show gets underway September 15. For more from the show, head to our dedicated hub.
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