“It’s simple: whatever the Porsche GT3 RS challenges, it destroys”

“You perspire as the 911 GT3 challenges your ambitions and flatters your inputs” “Proves that something other than a 911 can straddle the circuit/ road divide” “The BMW M4 GTS somehow seems a little, well, aftermarket”

I’m pretty sure the Mercedes has it covered both in a straight line and for overall lap time, but that doesn’t tell the full story. Once you’re comfortable in the Porsche, once you’ve had the confdence to switch of the systems and started to push it harder, it reveals something I think no other performance car can match. It gets up on its toes and genuinely feels like a racecar. It goads you into braking later and later, the motor keeps zinging into the upper-eights like you’re locked in a Supercup race. It makes you perspire as it both challenges your ambitions and simultaneously fatters your inputs. There are faster cars for sale, but, for the sheer buzz of lapping a circuit, nothing can beat a 991 RS.

Certainly not the M4 GTS. On the road, the BMW actually makes a little more sense – well, as much sense as a 4-Series with a gold roll cage can make. The real surprise on the road is the GT R. It carries no obvious compromise over the less exotic S – the ride is no worse and it didn’t have any rear seats to lose in the frst place. It’s the most comfortable car of the three over a long distance, and the motor ofers the most low-speed theatre with all those bangs and pops.

And the Porsche? Irritatingly good, given how keenly modifed it has been for the purpose of fast lapping. It has a radio, navigation and you can see out of it. The main impediment to using one daily is the way pedestrians tend too walk into things while gawping at that rear wing.

No other car has come as close to rattling the RS as the new AMG. It’s a stunning achievement on two levels. First, it unlocks the talent we always knew was stored in the AMG GT, and second, it proves that something other than a 911 can straddle the circuit/road divide.

But Porsche is the master of this trade through decades of experience, and the RS ofers a depth of both ability and personality that the Mercedes can’t quite live up to. It saddens me that so many of these brilliant driving devices lie garaged and commoditised awaiting some kind of fnancial reward because, when the petrol runs out, the RS will be considered one of the best driver’s cars ever produced.