There was only one candidate for the job. When we road tested it, the Porsche Panamera 4S Diesel did 0-100mph in 10.3sec, close enough for us to wonder if there was a way to make it the first diesel car ever to drop into single digits.
Our plan was simple: we’d cheat. All Autocar road tests are conducted with two people on board and a full tank of fuel. If I drove the car alone and with no more diesel in the tank than you might squeeze out of a small flannel, might that shave off those few annoying tenths while still being a representative test that any owner could repeat? We repaired to Bruntingthorpe Proving Ground in Leicestershire to find out.
I’d like to say there was a lot of skill in what followed, but beyond that required to read the handbook to find out how the launch control worked, there was none. I put it into Sport Plus, left foot hard on the brake, right foot hard on the throttle, waited for the dashboard to tell me the car was ready, lifted my left foot. And then the car just got up and fled.
Save for the physical forces on my body, there was remarkably little drama as the low-revving, torque-laden 4.0-litre twin-turbocharged V8 bowled the Panamera down the runway. So little, in fact, that I knew it had failed in its quest. Except it hadn’t. It had reached 60mph in 3.6sec and 100mph in a barely believable 9.3sec. Consider that the brand-new Porsche 911 Carrera S needs 9.4sec and the supercharged V6 Lotus Exige S 9.6sec and you have some sense of the level of performance that’s now available from the black pump. As someone who grew up in an era when diesels were so slow that it was often difficult to pull onto a fast-flowing roundabout, I could scarcely believe what I was seeing. So I turned around and did it the other way, just in case there was a force 10 gale blowing the Porsche up the runway. And indeed it was slower, but not much: 0-60mph in 3.8sec, 0-100mph in 9.6sec.
Perhaps just as remarkable was the way it would accelerate smoothly to a true 165mph so quickly that there is no doubting Porsche’s claimed 177mph top speed is typically conservative. Thirty years ago, we’d tested a grand total of one car with a recorded top speed higher than that: the ultimate version of the Lamborghini Countach, the QV, which managed to better the Panamera’s top speed by a single mile per hour.
But there’s more to this diesel even than that. When I think of what I want from a grand touring sports car, it basically comes down to effortless thrust, a stirring soundtrack and a massive range. This Panamera has it all. Compared with the more powerful but heavier and slower Panamera 4 Hybrid, with its coarse V6 motor and far worse real-world fuel consumption, I conclude there really isn’t much of a comparison to make. That is unless your motivation is solely financial and you live your life in that very particular way that allows you to make the most of the currently very benign company car tax system under which such cars now shelter. Everyone else should pay the extra and buy the diesel.