Porsche 718 Cayman GT4 and GT4 RS

I did this journey on Wednesday in a Porsche Cayman GT4 (I’m dispensing with the ‘718’) then did it all over again on Thursday, in reverse. The only real difference was that between the first journey and the second, I drove the new GT4 RS.

On the way up I decided the GT4 would be my daily driver if I didn’t have to drive other cars for a living. It’s more than quiet, comfortable, spacious and practical enough for my needs, and has the power and handling prowess to provide all I want on a public road too. And, unlike the RS which Porsche stubbornly (and mistakenly in my view) refuses to offer with a clutch pedal, you can get a manual GT4 which, indeed, is what I was driving.

All I’d change are the tyres. It comes with Michelin Cup 2s as standard which are wonderful boots for warm, dry roads and tracks. Actually they work well enough in the damp too, so long as you can retain some heat, but on public roads in March that’s not easy and if the road gets wet enough for there to be any chance of standing water, they are really quite limiting.

Meanwhile the Pilot Sport 4S lacks the ultimate grip in optimum conditions that you’ll only ever need on track, but it has a far broader operating window, which means more fun, more of the time. The good news is there is a 4S with the requisite Porsche-approved ‘N’ mark (and a Pirelli P Zero too); the bad that you can only have them fitted post-delivery.

I arrived at a damp Anglesey and skidded about in the GT4 for a bit, just for benchmarking purposes you understand. Then I made my acquaintance with the GT4 RS. You should never read too much into the stats, but the essentials are as follows. The RS costs approximately £30,000 more, which upgrades the 414bhp 4-litre engine in the GT4 to the full 493bhp motor from the 911 GT3, complete with its 9000rpm redline. Actually it’s 10bhp down on the GT3 motor, only because its mid-engined location means longer exhausts.

As discussed the PDK dual clutch is the only gearbox, but with a lower final drive and bespoke internal ratios, designed to ensure that this at least is one Cayman that will attract precisely zero criticism for its gearing being too high. And geared to add a fraction less than 23mph for every additional 1000rpm in top, it can consider that job done. It also means that at its 196mph top speed, the engine will be parked bang on its 8400rpm power peak, which is a rather old school and very proper way of doing it. So bravo for that.

Beyond the engine bay, the suspension retains the GT4 architecture with its GT3 front end (but strut-based from the 991, not the double wishbones of the 992) and a bespoke rear axle. But all its settings are RS specific. There’s a wider rear track and slightly bigger brakes but, interestingly, no change in tyre size.

There are the usual RS weight saving measures, in this case including a CFRP bonnet and front wings, reduced noise insulation, thin glass, lightweight door cards and so on, but the gains are not huge: at 1415kg (DIN) at the kerb, it’s just 35kg lighter than a similarly PDK-equipped GT4. Compared to the manual GT4, the RS is just five kilogrammes lighter.

Visually you can see the reprofiled front splitter, the wing vents and adjustable swan-neck rear spoiler, but actually there’s only an additional 60kg of downforce relative to the GT4 and that’s only if you put the wing in ‘performance’ mode. Truth is, this is not a car that relies much on aero for its grip, which is not necessarily a bad thing at all.

Besides, if it did its Nürburgring lap time might come uncomfortably close to that of the heavier, rear-engined 992 GT3. In fact there are other reasons the GT3 might maintain a gap of sorts: it has those wishbones up front, steering at the rear, an electronically controlled limited slip diff and fatter tyres.

Anyway, to work. And the first and most important thing to say is that this is a different kind of RS, and not just because it’s the first time the treatment has been applied to the Cayman. The conventional RS approach has usually been to provide just a little more power over the GT model from which it is derived, so there’s not much additional straight line speed, with most efforts instead being concentrated on how the car gets around a corner, with enhanced mechanical and aerodynamic grip. The GT4 RS takes a diametrically opposed route, to the extent that once you’ve driven it, the sensation of that engine and gearbox is by a distance the strongest impression it leaves.

For you must take it from me that while this engine has now been used in two generations of 911 GT3 (and one GT3 RS, plus the 911 Cup racer in essentially unchanged form), nowhere does it make a bigger impression than in the GT4 RS. And if that’s not what you were expecting, join the gang.

With all the vents and slats cut into the RS’s bodywork, it’s easy to miss the two air intakes cut into the rear quarterlights. Until the first time you put your foot down, that is, then you can’t escape them. You can literally hear the slurping sounds of the air around you being sucked into the motor, whose voice – I guess because it’s that much closer to you in this mid-engined car – appears to have been turned up to about 15.

It’s a mad, screaming, shrieking explosion of sound, inspiring at 6000rpm, thrilling at 7000rpm, euphoric at 8000rpm and borderline painful at 9000rpm. Put it this way, if there is a standard production road car (which this absolutely is) that generates more cabin noise than this, I really don’t think I’ve driven it. The voice of a Lamborghini Diablo SV is a distant cooing of a dove by comparison.

There’s something else here too. Because there’s so much more power, combined with substantially shorter gearing, there’s a massive jolt of energy injected into the chassis too. I’d say it brought the car alive, were that not to imply that the GT4 were somehow dead. But there is a new dimension, courtesy not just of the additional pace and poise, but just the sheer drama that powertrain brings. And the gearshifts are ridiculous, the changes banging through literally as fast as you can think them. Like the engine, it’s a transmission that’s worthy of a racing car.

And yet, once we were done, I drove it up to our overnight halt in Holyhead. Tired after a long day flogging across Wales and then around the track, I just ambled along the A55 dual carriageway into town. And it was just fine. No, the ride’s not quite as good as that of the GT4, but it’s perfectly acceptable, and that maniac motor? On part throttle it’s just perfectly acceptable, just the brevity of the overall gearing raising its voice a touch.

The important point here is that the car is usable, and eminently so. Despite the insane cacophony on track, on the way there and back the car is by no means uncivilised. It has a big boot too: a trip out to the Nürburgring would not be purgatory at all. It would be a pleasure.

So the following morning I jumped back into the GT4 and headed home. On the track, it really did feel like the poor relation because in that environment you can use all that the RS does so well to the full and all the time. But you can’t on the road. And here, the slightly more compliant, slightly quieter and, lest we forget, clutch pedal-equipped GT4 once more felt every bit as good as it had on the way up.

Actually, it’s surprising how different these cars are, more different indeed than even a 991.2 GT3 Touring and the equivalent GT3 RS. To the extent that it slightly undermined my purpose of driving one, which was to ask whether the RS really could be worth that much more than the GT4. But, actually, it’s not that kind of car. You could use a GT4 RS as a daily, but it would be so rare that you’d get to really enjoy what it does best, which is to howl at you when you’re flat-out on the track.

A GT4 however is perfect in that role, a car that can be used to the full on the right road. The question the GT4 RS actually poses is not whether it’s worth £30k more than a GT4, but whether for £23k less it’s not actually a better car than a 911 GT3. And on that, I will get back to you.

Porsche 718 Cayman GT4 RS

Engine: 3996cc, 6-cyl, naturally aspirated
Transmission: 7-speed dual clutch, RWD
Power: 493bhp @ 8400rpm
Torque: 332lb ft @ 6750rpm
Weight: 1415kg

Power-to-weight ratio: 349bhp/tonne
0-62mph: 3.4 seconds
Top speed: 196mph
Price: £108,370

Ti rating: 9/10

Porsche 718 Cayman GT4 

Engine: 3995cc, 6-cyl, naturally aspirated
Transmission: 6-speed manual, RWD
Power: 414bhp @ 7600rpm
Torque: 310lb ft @ 5000rpm
Weight: 1420kg (1450kg PDK)

Power-to-weight ratio: 292bhp/tonne
0-62mph: 4.4 seconds (3.9sec PDK)
Top speed: 189mph (188mph PDK)
Price: £78,750

Ti rating: 9/10