THE BOXSTER is extolled and the 911 drowns in a sea of purple prose, but it’s the Cayenne SUV that keeps Porsche viable, by accounting for 50 percent of all sales globally. And just to rub the purists’ upturned noses in it, the biggest seller is the humble V6 diesel. The good news is that Porsche has obviously been mulling over this issue, hence the arrival of its first ‘performance diesel’. As such things go, the S Diesel is a pretty easy proposition to understand: take a Cayenne S petrol V8, unbolt the engine and drop in the Audi 4.2-litre twin-turbo V8 already used by the Q7 and A8. Of course, to live up to Porsche’s position within the VW Group hierarchy – topping Audi, no matter what – the DOHC 24-valve engine has been tweaked to kick out an extra 23kW and 50Nm, taking outputs to a sizeable 281kW and stupendous 850Nm. No diesel SUV boasts a higher torque number.