How to create the ideal driver’s car

We’ll go to weight next. A 300bhp car weighing one tonne has exactly the same power-to-weight ratio as a 600bhp car weighing two tonnes so, all other things being equal, both will accelerate at the same rate. But which would you rather drive? I’ve met plenty of marketing people who are obsessed with power, but no engineers. And I’ve met no internationally respected car engineer who was not obsessed with weight, or loss thereof. As others have observed, the formula is simple: more power just makes you accelerate more quickly; losing weight makes the car not only quicker everywhere but it is also probably the single most crucial component of what road testers call the car’s feel.

What about grip? It’s peculiar how hard manufacturers strive to provide their cars with ever more grip, making less accessible by degrees that lovely feeling of a car nearing the limit of its adhesion. Then again, a car with so little grip that it can’t carry meaningful speed is a perpetual frustration. A middle ground is required.

Balance is a vital ingredient in this melting pot and, once more, what’s needed is something between the extremes. A car that understeers too much will always be boring; one with excessive oversteer will always be dangerous. What we all want, even the drift jockeys among us, is a car that just steers unless commanded to do otherwise by its driver.

Practicality is perhaps an unexpected inclusion but it’s essential. You can have the most entertaining thing on wheels, but if it’s so impractical that you can’t take it anywhere overnight or don’t want to drive it in less than ideal conditions, that’s getting in the way of your fun. And what if your other half refuses to travel in it? Or resents you owning it? That ain’t fun, either.

Britain's Best Driver's Car 2016 - the final three

Does ride quality affect your enjoyment of a car? You bet it does and not just because being uncomfortable always makes life less fun. If the car is so stiff that it actually pings off bumps in the road, affecting its stability, that can be one of the most joy-killing faults of all.

Then there’s all the vital detail stuff: which wheels should be driven, where should the engine be located and would you prefer manual, paddle shift or automatic gears? Has electric power steering now caught up with hydraulic systems for pure feel? And what about visibility? Can you really enjoy to the full a car that you can’t see out of properly? And what kind of noise should it make? And, yes, I guess I have to let good old power have its say, too, although in fact, when it comes to having fun on four wheels, torque is a far more valuable commodity.

When I fed all of this data into the admittedly somewhat capricious computer between my ears, it didn’t take long for an answer to appear. Although it by no means achieves top scores in every area, it seems, on paper at least, that the Porsche Cayman is the car that scores highest in most areas, emerging in theory in the sweetest of sweet spots that a driver’s car can currently occupy.

Even the less than eagle-eyed among you will have spotted that the particular Cayman we have chosen to illustrate this point is not the current car. It is possible that, even with the controversial fourcylinder engine behind the driver, the current 718 Cayman S could do sufficiently well in other areas to still be considered the optimum driving machine for all the reasons already laid out, but with a Cayman GT4 available to us and every nod, tip and wink we’ve had about the next one suggesting that it, too, will have a normally aspirated six-cylinder engine, it seemed too good an opportunity to ignore.

Britain's Best Driver's Car 2016 - the winner

Now I know Cayman GT4s still cost way more than they did when new (they start at around £80,000 at the moment) so it’s not going to score highly on the financial accessibility front, but really it’s here to represent the Cayman generally, and if you’re not too fussy about age and mileage, Cayman ownership can be yours for as little as £10,000.

And really it’s the things common to all Caymans that stand out most when you first drive one, even the GT4: the superb all-round visibility, compact dimensions, perfect driving position, comfortable ride and the fact that, with the space in the nose and the hatch behind you, the car is actually very well suited for long journeys and holidays.

It’s light, too, the GT4 tipping the scales at just over 1400kg. That’s not bad for a car toting a 3.8-litre sixcylinder engine. A rear-drive Jaguar F-Type V6S coupé with the same 380bhp weighs almost 1600kg.

What’s clear from all this is that Porsche’s strategy is to get the fundamentals right before doing anything else. Make your car too heavy and you can replace the performance but never the feel. Make it too wide, or too hard to see out of, and, however well you engineer the result, it will be forever hobbled by these shortcomings.

Having established such firm foundations, Porsche then just builds from there. In any Cayman, it’s not the big stuff you notice, like how fast it will get down a road or around a corner. It’s the nuances. The gearshift is simply the best manual change on sale and the sound of the flat six the sweetest music to your ears. Even details such as the size of the steering wheel (reassuringly large), its gearing (refreshingly slow) and the material used to upholster its rim (firm to the touch so as not to damp out feel) smacks of an engineering team that has just thought harder about what really matters in such cars.

Porsche Cayman GT4 2015-2016 review

And then there’s the chassis. In theory, a front-engined car with a gearbox between the rear wheels giving a slight rearward weight bias probably offers the best chance of achieving perfect real-world balance, but it’s achieved only at the expense of nimbleness (because the main masses are not concentrated in the middle of the car), traction relative to a mid or rear-engined car and steering response and feel. In reality, you won’t drive a car that feels better balanced than a wellset-up Cayman. Mid-engined cars are meant to be more inherently tricky because of their low polar moment of inertia, but the Cayman is so good at signalling when it is about to slide and then slides in such a linear fashion that it provides all the advantages of a mid-engined car while being easier to drive than most fast front-engined machines.

If the GT4 or any other Cayman should be marked down on this scale, it can only be that its lack of rear seats will obviously mean there are people into whose lives a Cayman will simply not fit. But for those whom it does, right now and so far as we can determine, a Cayman hits the driving pleasure sweet spot better than anything else we can think of.

Autocar's ideal 'sweet spot' car would...

-  Be front engined and rear-wheel drive.

-  Be no more than 1750mm wide.

- Weigh no more than 1300kg.

- Have a normally aspirated flat six, straight six or V8 engine.

- Have a manual gearbox.

- Have space to spare for two and a fortnight’s luggage, and four in an emergency.

- Have a power-to-weight ratio of 200bhp per tonne or better.

- Have hydraulically assisted steering.

- Have sufficient ride, refinement and equipment to perform credibly as an everyday car. 

Other 'sweet spot' contenders:

BMW M2

It’s almost as good to drive as a Cayman but with the added bonus of usable rear seats. The creamy straight six engine hardly feels turbocharged at all, the chassis is endlessly playful and the ride quality is surprisingly good.

MAZDA MX-5 RF

Before the RF came out, the MX-5 would have found it hard to make this list because of its soft-top. But the RF’s roof makes it an everyday car so you get to spend more time enjoying all of those things the MX-5 does so brilliantly.

TOYOTA GT86

Proof that power isn’t everything. Light, compact, brilliantly balanced and dripping in character, the GT86 ticks a lot of boxes on the sweet spot wish list, none more convincingly than its super-low list price.

VOLKSWAGEN GOLF GTI

The fact that this breaks so many sweet spot rules (all its weight up one end and incorrect-wheel drive) yet still ends up on the list speaks volumes for how hard VW has worked on everything else. A real driver’s car in a family-friendly shell.