There's nothing like a bit of needle from the opposition. In the face of the astounding outputs now announced by the rivals McLaren P1 and LaFerrari, Porsche has found some more poke from the race-bred V8 engine in the 918 Spyder. It has also juiced-up the electrical systems. Result, it's now rated at a total 887bhp, almost 100bhp up from the original expectation.
That's 608bhp from the engine, 149 from the rear electric motor and 129 from the front one. Meanwhile, the weight has been cut, to 1640kg in this production-intent prototype, thanks to the kg-shaving 'Weissach Pack'.
The rest is as we've reported before. Which, because of the 4WD as well as the plug-in hybrid system and four-wheel steering, makes it the most complicated car I can think of.
But right now, strapped in, behind the wheel and pushing the throttle on the corner that flows into the straight at Porsche's Leipzig track, I'm occupied not with complication but with acceleration.
Of a pure and savage kind. The zero-to-125mph number is under eight seconds. That's a whole second better than Porsche's original prediction. The flat-crank V8 jettisons its exhaust from a pair of upward-aiming pipes just behind your head. It's hollow and gutteral at low revs, then yowls with primal urgency as it approaches the 9150rpm limit. It makes 132bhp per litre, by the way. Without a turbo or supercharger in sight.
Such a revvy engine would normally leave you with a torque hole, but the 918's electric motors, which do their best work at low revs, come to its aid. With the electric and combustion combination, there's torque everywhere, right round the rev dial. By say 4000rpm, it's already generating huge acceleration, so that downshifts are something you do out of pleasure rather than obligation.
Here we get into an unsung benefit of the hybrid powertrain. Sure you could get this sort of any-gear thrust out of a turbo engine, but it would give you lag. Or you could use a massive N/A engine. But then it wouldn't rev.
The 918 is an utterly distinctive experience, a car that always answers the call of your throttle foot, almost before you've even asked. This has a slightly odd effect. Because it's never lethargic, its colossal energy is slightly disguised. The 918 also has slip-free 4WD traction out of slow bends, again reducing the drama.
I should have paid more attention to this. In my first laps in the 918, squally rain has been sheeting down and the track, like the Tory consensus on the EU, has just turned treacherously slippery. I come out of the slow bend before the pit straight. I nail it, and the 918 catapults down the straight. Deceived by its disdainfully effective speed, I'm bearing down on the soaking-wet 180-right at the end of the straight far faster than I meant to.
I assess the size of the run-off area, and contemplate the end of my career in testing other peoples' expensive cars. (With the Weissach pack the price is around £726,000, but they say this prototype cost nearer £3 million to build.) Still under brakes, I turn the wheel. In we go. Out comes the tail. Too late in the day, I feather the brakes and administer a shabbily gauged dose of opposite lock.
The 918 saves me. No idea exactly how. But it's a combination of the following. A very low centre of gravity, and good suspension geometry, and an ultra-stiff all-carbon structure. The fundamentals, in other words, are right. Then the clever bits: a stability system that corrals the efforts of three other systems: front-rear torque vectoring via the electric motors, an electronically controlled rear diff, and finally four-wheel steering like on the new 911 turbo and GT3.
And so on we go. It turns out that in the wet the 918 is a bit of a hilarious skid-bunny, sliding out of corners as well as in, but always giving you a helping hand. What's remarkable is how Porsche has managed to integrate all these complex systems. Remember, there's a petrol engine, in tandem with an electric motor, and they both drive through a seven-speed transmission. At the other end of the car another electric motor with a single-speed transmission. Just imagine the processing task, to control all three of them and produce a seamless and natural result.
Later, I do some dry laps. Now it's all about agility and epic grip, and the way the steering feels as you nudge the edge of it. In a long bend you get no oversteer, just a widening of the line at the limit. You can cancel that by a slight lift, and then more power if you want. You never really feel pitch or roll. It's an immensely friendly car when it's being worked hard. Much more so than the Carrera GT.
It's not perfect. The brakes have a special blending valve in them. If the battery isn't fully charged, the motors are reversed to give 0.5g of regenerative braking, which is far more than any electric or hybrid car I've driven before. Beyond 0.5g the wheels brakes, carbon discs, come into play. If the battery is full then the discs do all the work. But the pedal feel is a bit unpredictable. The engineers know it and say it'll get better. The purpose of such strong regen braking, of course, is to harvest more free energy, and offer a KERS boost for longer. It's done the Nordschleife in 7'14".
If you don't spend the efficiency of the hybrid/KERS system on banzai acceleration, you can spend it on reduced fuel consumption. Switch to 'hybrid' mode and the engine cuts in and out, and the gearchanges are managed automatically. The engine, when running, is used both to drive the rear wheels and charge the battery. Another bewilderingly complicated task for the control units, again handled smoothly.
Finally, there's pure electric mode. The battery can be charged from a special wall-box in under half an hour, which will give you about 15-20 miles e-drive. In that mode you've got 268 horsepower, distributed between four wheels. It's a smooth, brisk and relatively silent mode, and offers 0-60 in about eight seconds. Mind you as with all electric cars the poke mostly makes itself felt in low-speed acceleration. Beyond about 60mph it's tailing off. Even in e-mode, if you floor the throttle the car assumes you want more, so the V8 instantly starts and chimes in.
E-mode is hardly sporty. It's possible in future it'll get you into city centres where combustion cars are banned. But basically e-mode is a sideshow, a hack to get headline-grabbing CO2 numbers, and a by-product of having the electric motors on board to improve the car's dynamics when the V8 is running.
It might be wider than even a Cayenne, lower than a serpent and hard to get into, and it might have such poor rear vision that it really does need the standard rear-view camera, but actually the 918 is not generally intimidating. For instance, forward and lateral vision is good. You sit fairly upright, and the screen pillars are thin and well back. Plus the lovely curve of the front wings swell up into your field of view, so you get a strong sense of the car's size and position whether you're manoeuvring it or aiming it at an apex. The cockpit design is sensible, too. It even runs a brand-new navi-comms-entertainment system, with a lovely swipeable, touch-to-drag, pinch-to-zoom screen.
In fact Porsche is making quite a big deal of the 918's practicality. It's comfy enough, it's got this great infotainment interface, and it's got an easily removable roof. It's even got a cup-holder. The e-mode makes it stealthy when that's what you want. The 4WD makes it good in the rain.
But of course they would say that, now that they know the McLaren and Ferrari are madder and faster. The 918 is without question an utterly fascinating science project. But the question is, how sensible must an insane hypercar be?