The Autocar sports car World Cup - the final

For such an extraordinary device, the 540C is the invisible McLaren. It was commissioned at a time when the company was a lot less confident about its future and place in the world than it is now and was  designed to ensure the company had something that could sell directly against the 911 Turbo. But it costs nearly £20,000 less than the 570S to buy, despite costing McLaren hardly anything less to build. Which is why there is no GT version of the 540, nor will there be a Spider. Given its time again but with the benefit of hindsight, doubtless McLaren would not have built it at all.

Which is exactly why it is such a bargain. The biggest difference between it and the 570S is that its engine produces 30 fewer horses, but because the 570S’s additional power is largely at the top end, you’re not going to notice what you’re missing unless you’re able to drive the wheels off both one after the other. Of course, we have done exactly this and it’s interesting to see what a difference that 30bhp makes, because even among cars with outputs in the mid-500bhp bracket, it is substantial; but unless you’re going to go redlining everywhere, the 540C does just fine.

And against the 911 GTS, where its advantage is closer to 90bhp, it offers a different category of performance. Don’t read too much into the 911’s 4.1sec 0-62mph time, because were you to equip it with a paddle-shift gearbox like the McLaren’s, that time would fall swiftly to 3.7sec, closer than you might think to the 540C’s 3.5sec sprint. But in reality, the McLaren really does feel much faster. It has more turbo lag, but when it kicks in a lower gear, it provides you with that uncomfortably hurtling feeling that is the hallmark of all exceptionally fast cars. And quick though the 911 is, it can’t quite do this.

But nor does it need to. Truth is (and we tried this, too), that so long as sane drivers are at the wheels of both cars, the GTS will sit neatly on the tail of the 540C from dawn until dusk. Sure, around a track, we’d expect the Brit to drive away from the German in short order, but in the always restrictive environment of even quiet moorland roads, both cars have potential to spare. The fact that the McLaren has rather more of it is really neither here nor there.

Nor can the McLaren make any subjective claim to powertrain superiority just because its engine has more cylinders. It is the Porsche engine that sounds better at all speeds and it is Porsche that provides a choice of two or three pedals in the footwell. And with a manual gearbox as good as that now used by Porsche, that is a sizeable point in its favour. Yes, the McLaren shifts gears pretty instantly in both directions and there is certainly pleasure to be had from the uninterrupted progress that results, but physically to use a lever to select the next ratio is always going to be a more involving process. And few levers find their way around the gate more sweetly than that of this Porsche. For a sports car, a pure driving machine, this stuff really counts.

But so does the way a sports car feels in your hands. And, of course, the 911 is exceptional in this regard, especially in this lightest spec a GTS can be. Its steering is pin-sharp, its damping superlative. If you want to feel confident while driving a rapid car quickly, there’s no better place to shop.

On the other hand, if you want to feel like a superhero, you’re going to need the McLaren. Its handling is better than exceptional: it is incredible. Porsche abandoned hydraulic power steering years ago but McLaren proudly states it’ll be the last manufacturer on earth to embrace electric assistance. Drive the 540C on an undulating road and you’ll see why. The feel the helm provides, that sense of contact with the road it imparts, is such that when you jump back in the 911, it’s like you’ve donned a pair of thick gloves. It still does exactly what you want and when you want it to, but that level of communication is missing. You get more through the McLaren’s carbonfibre shell, too, its ultra-stiff construction providing the perfect platform for its exquisitely tuned suspension to work upon.

There’s also another thing, important even in the realm of the sports car. The McLaren feels special in a way the Porsche does not. Look at its stance, its styling, its partly exposed carbon shell, its low-slung driving position, its elegant yet futuristic interior design: all speak of an exclusivity, a quality of experience and a likelihood of retained memories the 911 cannot touch. Yes, we think this second-generation 991-series is one of the prettiest in 911 history, but it’ll take more than that, centre-lock wheels, a bit of Alcantara and a few GTS badges to bridge the gap – no, gulf – between it and the McLaren in this respect.

Yet other gulfs exist, too. Sports cars must also be usable, and while we applaud McLaren for giving the 540C a big boot, such exceptional visibility and (rubbish sat-nav aside) a pretty impressive ergonomic environment, it does not have 911-grade visibility, nor its ground clearance. It’s a little harder to enter and much, much harder to exit. You can’t thread it through gaps like you can the Porsche and, of course, it has no rear seats. By the standard of mid-engined exotics, the McLaren Sports Series (540/570) is probably the most practical and usable of them all, but a 911 it is not.

Which is why, were this a conventional twin test, we’d factor in the price differential and award victory, by the smallest margin, to the Porsche. Recently, we named the GTS our favourite car on sale and nothing we’ve seen here changes that.