Practicality 2.3/ 5

IN an effort to make the 570S as easy to live with as possible, Mclaren has increased cabin space over the more expensive 650’s. This means the driver and passenger get as much head, leg and shoulder room as in the Audi, while the large windscreen and low dashboard help create a reasonably airy environment. Elsewhere, you’ll find a couple of handy cup-holders, a centre console trinket tray and a fairly large glovebox housed behind a slightly flimsy-feeling lid.

The Mclaren’s deep front boot’s 144-litre capacity is bigger than both rivals’, while behind the seats there’s also a useful parcel shelf that will comfortably accommodate a couple of squashy holdalls.

Road tests

FOR more than four decades, the 911 Turbo has been the flagship of Porsche’s sports car line-up. Combining electrifying pace with everyday civility, the fastest 911 has always been a supercar for all seasons. Now in its sixth generation, the range-topper has been treated to a mid-life refresh that brings it into line with the rest of the 991 range. In the Turbo S guise tested here, that means power rises by 20bhp to 572bhp, while the price increases by around £1,500 to £146,478.

Styling 4.0/ 5

THE current 991-generation 911 has been around since 2012, yet it can clearly trace its roots back to the 1963 original. The raised front wings, relatively upright windscreen and sloping tail are unmistakable 911 cues, as is the traditional rear-engined layout. Yet clever evolution of the design means the car still looks modern.

Turbo and Turbo S models are identified by their wider rear wheelarches that house vents for channelling air to the 3.8-litre twin-turbo engine, a deeper front bumper that includes a powered air dam, and a retractable spoiler mounted to the engine cover. These latter two items are part of an adaptive aerodynamics package that automatically adjusts to balance the airflow around the car.

Other enhancements include quad exhausts and the 20-inch alloy wheels that cover the 911’s standard carbon-ceramic brakes. Yet despite these muscular additions, the Turbo S blends into the background when parked alongside the Mclaren and Audi.

Inside, the Porsche feels just like any 911, which means you benefit from peerless build quality, top-notch materials and a driver-focused layout. As ever, the traditional five-dial layout, perfectly sited controls and excellent visibility are all present.

In fact, the only clue to the car’s flagship status is the discreet Turbo S logo on the rev counter. As with other models in the recently revised 911 line-up, this model gets Porsche’s new touchscreen infotainment system, which features clearer graphics and is easier to use. Standard kit is generous, too, with sat-nav, leather trim, climate control and heated seats.

Driving 4.6/ 5

THE Turbo S’s engine shares a 3.8-litre capacity and twin-turbo layout with the Mclaren, but that’s about as far as the similarities go. As with all 911 models, the powerplant is located at the very rear of the car and features a flat-six layout.

Revisions to the turbos have resulted in a power boost to 572bhp, while torque remains unchanged at 750Nm. In combination with the car’s sophisticated four-wheel-drive transmission and PDK twin-clutch gearbox’s launch control function, it allowed our 911 to howl from 0-60mph in a mere 2.9 seconds.

Even more impressive was the 911’s in-gear pace. The Porsche delivers its maximum torque at a mere 2,100rpm – much lower than its rivals – which helped our test car accelerate fastest from 50-70mph in fifth, despite a much taller ratio than the R8.

In the real world, this mid-range muscle translates into mind-scrambling overtaking pace. The tuneful flat-six isn’t as raucous as the Audi’s V10 – plus it lacks the alert low-speed response – but once its turbos start spinning the 911 accelerates with real violence. The sensation of speed is enhanced by the seven-speed gearbox, which delivers seamless, rapid-fire shifts. Yet despite this explosive power delivery, the Turbo S rarely feels intimidating to drive. Compact external dimensions and excellent visibility play their part, as does the sophisticated all-wheel-drive transmission that constantly shuffles torque to deliver the best traction. The steering has a meatier feel than the Audi’s and delivers more feedback, plus there’s tremendous traction and grip. Driver confidence is further boosted by the standard adaptive dampers and active anti-roll bars, which virtually eliminate movement in corners.

The S also has a four-wheel-steering set-up that boosts turn-in at low speeds and increases stability through fast bends, helping the 911 feel lighter on its feet than its hefty 1,675kg kerbweight suggests. It can still bear its teeth, however.

Switch off the electronic driver aids, and you’ll need to be quick with your inputs to counter any slides. That engine over the rear axle acts like a pendulum, swinging round the back of the car.

For most of the time, however, the Turbo S is completely docile. The ride is firmer than the Mclaren’s and there’s a fair amount of tyre noise, but the engine din subsides at a cruise and the PDK gearbox serves up seamless shifts. The brakes are also smoother and more progressive, although they deliver eye-popping stopping power, hauling the Porsche from 70-0mph in only 36.9 metres.

Ownership 3.2/ 5

PORSCHE is a consistently strong performer in our Driver Power satisfaction surveys. In 2016 buyers rated it seventh out of 32 brands, plus its garages secured an excellent eighth in our most recent dealer poll.

The 911’s six airbags, two-stage stability control plus upgraded brakes and suspension inspire confidence, as do its four-wheel drive and four-wheel steering. It’s also the only car here available with an autonomous emergency braking function – but only when you add the £1,278 adaptive cruise control.

Running costs 2.1/ 5

AT £146,478 the Turbo S is the most costly car on test, yet it’s not quite as well equipped as its rivals. Our experts have also calculated that the Porsche won’t hold on to its value as well as the Audi.

And while its CO2 emissions of 212g/km are the lowest here, as the 911 has the highest price, top-rate business users will pay more in Benefit in Kind tax. Still, we recorded 24.7mpg economy, which is excellent given the car’s performance. Also, its servicing costs are the lowest of this trio.