Vodka or single malt? Sandwich or salad? Or perhaps insert any other pair of apparently competing entities that appear to create the perfect rivalry, but which under more intense scrutiny might not be quite such natural competitors.
It would be easy to become mired in the raw numbers of the P1 and the 918. In fact it would be interesting to become lost in the numbers because they are overwhelmingly impressive, but only two facts need really be digested: the P1 has a far superior power-to-weight ratio, and the Porsche takes the business of being a genuine plug-in hybrid far more seriously. In fact a clever PHer called CraigMc has deconstructed each electrical system here in the comments following the P1 vid.
If the Porsche is more technically impressive...
Herein lies the core difference between the cars. I genuinely believe that the 918 exists as a means of demonstrating what Porsche can do right now, and what it might be capable of delivering in the near future. Its gestation has been terribly complicated and politically divisive (not everyone in Weissach is a fan of electricity in this type of car, nor is it selling in the numbers Porsche would like or have us believe) but the resulting product is far, far more compelling than we could ever have imagined.
The P1 uses electricity for simpler means - to plug a gap where once there was no torque. Yes, McLaren needs to make a connection between its F1 KERS expertise and the road car side of the business, but once you've experienced the combination, it's hard to reach any conclusion other than having experienced the powertrain template for the next generation of performance cars. So in a way, the P1 is just as much a rolling technical seminar - just a far less ambitious one. Does that make it less relevant or impressive?
I suppose that depends on how far you see these technologies spreading and what you view as being the fast road template of the future. The 918's dynamic characteristics are both defined and limited by its four-wheel drive and front electric motors. On a circuit, each initial braking moment feels a little unnatural and even though the calibration work on the torque vectoring chassis is exceptional, this doesn't feel like a normal sports car. Whereas the P1 genuinely does. In fact it feels better than a 12C.
...it's the McLaren that tugs the heart strings
But out in the real world? Well, everything fast is moving to all-wheel drive, so you'd have to say that Porsche's front axle mounted motors probably preface the future, whereas the P1's rear-drive architecture is more limited in its scope. Conversely, I personally think that the amalgamation of electricity and forced induction in the P1 is perhaps even more significant than the 918's chassis tech. Here we are locked in a 30-year search for an end to turbo lag - variable vanes, anti-lag, high compression - and it's volts that have finally solved the problem. The P1's throttle response is one of the Eureka moments of my motoring life.
More interestingly, I think these cars force us to reappraise what it is we expect from a car of this type. Should it just be bat-excrement fast? In which case everything bows to the Venom GT. Should styling be all that matters? In which case Pagani and Lamborghini will sell you something more outrageous. Sadly for Porsche I do think that raw numbers matter, and both the P1 and the LaFerrari (assuming the claims are correct) are much faster in a straight line. And even in this new universe of the reformed eco-hypercar, I don't think many owners fancy defending their lack of oomph, all things of course being relative, in terms of increased all-electric range. I personally think the 918 is the prettier, but that's subjective and again, might be too little compensation. I've never met anyone who has told me they want to own the third fastest hybrid hypercar.
It's pretty but slower than the two main rivals
But I do think the first time you waft silently in a 918 is, and I'm sure many people will find this perplexing, actually just as impressive as the first slab of full-force acceleration.
The nitty-gritty of driving is actually the clearest-cut aspect of this supposed rivalry. The P1 is faster, more natural and more exciting. Its steering is clearer and more enjoyable. If the P1 didn't exist the 918 would currently stand supreme, but even then some of its handling traits at high speed really do require the chassis electronics to be activated, and the regenerative braking adds interference. Both could conceivably be used every single day, and the Porsche's cabin is much more spacious and luxurious. It's also a full-Targa, so will be much easier for to use for the LA cruise.
I think it's also interesting to try and understand and anticipate how these cars will be received by tomorrow's history books. Again, I think they will be kinder to the P1, simply because I think it will be a long, long time before any 'regular' supercars will match its level of performance. However, were Porsche to build the mid-engined 458 rival we all know it has planned, and that car was to be propelled in a similar way to the 918, then it's quite possible that it would be nearly as fast and, with the benefit of everything learned on the 918, its chassis could be even more impressive.
As a driver's car there's a clear winner
Don't get me wrong - I stand by
everything I said
about the 918. But driving the P1 has made me realise that much of my emotional response to the Porsche was couched in terms of admiration and surprise that the team of engineers could make something so infernally complicated work at all. Whereas I was just completely blown away by the P1's performance, and the way I connected with it as a driver.
I suppose we ought to drive the one from Maranello to complete the triumvirate. I'll work on that.