Both engine types will reportedly be built around a shared architecture, with a 90-degree angle between the two banks of cylinders. The initial suite of engines will feature cylinders with a volume of 500cc each, meaning that the V6 will be 3.0-litre unit, while the V8 will be a 4.0-litre motor.
As is currently the vogue, the new V6 and V8 engines will be assisted by a gas-driven turbocharger to improve fuel efficiency, power, torque and performance. Later iterations may feature an "electric turbo" to eliminate lag and improve low RPM responsiveness.
The new V6 and V8 engines may scaled down at a later stage too. Some sources have indicated to the British magazine that Audi is also working on a fuel economy-focussed version. This V6 engine is said to displace just 2.5 litres and feature Atkinson-cycle combustion.
No indication has yet been given about when the engines will start appearing in production Audi and Porsche vehicles. It's likely that when once the new petrol engine family starts trundling down the factory line, it will also appear in select Bentley and Volkswagen models.