It was a bit of a surprise yesterday when Audi went and dropped initial details and photos of the upcoming S6 and S7 range. That initial focus was entirely on the diesel versions bound for Europe. 24 hours out from the drop, we’ve been able to get our hands on a few more photos and a few U.S. details.
It’s probably worth beginning with the spec. Audi has ended its diesel business in the USA, focusing instead on TFSI turbocharged engines, TFSI plug-in hybrids and full electric offerings. With no room for diesel, America and other export markets needed something different than the 349 hp / 516.3 lb-ft 3.0 TDI slated for the European market offerings.
To that end, our pal Mike Juergens pointed out after a thorough analysis of yesterday’s press release, that Audi did confirm basic details of the U.S. spec engine. Here’s a quote.
For the United States, Asia and Middle East: the S6 and S7 models with 2.9 TFSI
In overseas markets – to reflect local customer preferences and driving profiles – the S6 and S7 will be available as the 2.9 TFSI with an output of 450 hp and 600 Nm (442.5 lb-ft) of torque. Like the TDI models, the V6 gasoline version will be equipped with both the EPC and the 48-volt MHEV system, for more performance and efficiency.
Looking at the basic spec, it appears the American S6/S7 will get an engine similar to the 2.9-liter V6 found in the RS 5. That engine is currently the only 2.9-liter petrol engine offered by Audi.
Something not shared with the RS 5 is mention of the “EPC” or “electric powered compressor”. It is an electric turbo. The current RS 5 doesn’t have a 48-volt electric system, but the C8-based A6 and A7 do. Therefore, Audi is able to integrate electric turbocharging into the 2.9 TFSI bound for the next S6 and S7.
Here’s what the press release said about EPC as it applies to the 3.0 TDI. Though power figures and engine RPM numbers won’t apply, the basic concept will and so it’s worth revisiting.
Spontaneous helper: the electric powered compressor
The electric powered compressor delivers high starting performance. As well as very vigorous acceleration, the electric supercharger provides a repeatable boost function when accelerating. This means the EPC pre-empts any hint of turbo lag, and enables high responsiveness and powerful acceleration in every driving situation.
The EPC’s response time is under 250 milliseconds, its peak output is seven kilowatts and its maximum speed is 70,000 rpm. The electric turbocharger’s boost function extends all the way to an engine speed of 1,650 rpm. Thanks to dual supercharging, in other words the EPC working in tandem with the exhaust turbocharger, the full-size S models achieve a constant torque of 700 newton-meters (516.3 lb-ft) across an engine speed range of 2,500 to 3,100 rpm. The EPC supports the TDI’s turbocharger whenever there is insufficient energy in the exhaust gas for a spontaneous torque buildup – when starting off or accelerating at low load, from a low engine speed.
The EPC, which visually resembles a conventional turbocharger, is mounted directly on the engine in the intake air path behind the intercooler. In most operating statuses it is circumvented by a bypass. However if the load demanded by the accelerator is high and the energy available on the turbine side is low, the bypass valve closes, guiding the intake air to the EPC. The compressed air flows directly into the combustion chamber.
The result: spontaneous response and impressive pulling power when accelerating, overtaking and for changes of load. That places the entire power of the 3.0 TDI engine immediately at the driver’s disposal whenever they require it. In everyday driving, the technology avoids frequent downshifts, keeps the engine speed level low and suppresses the turbo lag to which a conventional exhaust turbocharger is susceptible.
The EPC paves the way for an impressive starting performance. The V6-TDI complete with EPC propels the new S6 Sedan from 0 to 100 km/h (62.1 mph) in 5.0 seconds, with the S6 Avant and S7 Sportback taking a tenth of a second longer over the standard sprint. The top speed is electronically limited to 250 km/h (155.3 mph).
Next up are the photos. Audi regularly follows a new release with different media and photography available on their home market (Germany) consumer website. In as much, we cruised over to Audi.de in order to see what we could dig up… and we weren’t disappointed.
Though configurators aren’t live yet so that we might dive into all of the complexities of equipment and option packages, we did find new shots revealing equipment such as unseen wheel designs and even what looks like the use of one’s mobile phone as a key fob in the mix. We’ve added all of the photos here, but you’ll find more information and slightly higher-resolution and non-labeled versions downloadable over there.
We are including also unseen photos of the S6 Avant here. To be clear, we don’t expect the S6 Avant to come to the USA even though the A6 allroad and RS 6 Avants are very likely at this point. Even still, we figured our readers want to see everything, and so we’ve included it here.