How quick is the new Audi R8 4.2? Owen Mildenhall puts it up against the Porsche 911 Carrera 4S on track to find out. 

Audi R8 4.2
Price: from $287,000 (auto)
Engine: 4.2-litre V8 petrol; 316kW/430Nm
Transmission: 7-speed dual-clutch auto, AWD
Thirst: 12.4L/100km; 289g/km CO2

Porsche 911 Carrera 4S
Price: from $264,750 (auto)
Engine: 3.8-litre flat-six petrol; 294kW/440Nm
Transmission: 7-speed dual-clutch auto, AWD
Thirst: 9.1L/100km; 215g/km CO2