On most roads you’ll have to use your imagination to recognise how much better the Porsche Carrera S is

Mark is one of the expert instructors at the Porsche Experience Centre, Silverstone. The day was wet. I did notice I was catching the two cars in front, so must have been doing something right – or they were doing something wrong. No matter. We can all pretend and it gives a few morsels of conversation back in The Smallbore Bar. “Yarr, lost it a bit coming out of Vale but the electronic stuff nipped in and saved the day.”

This is another new 911 which looks pretty much like the last one in a process of evolution which takes the legendary rear-engined car a step nearer perfection. It is bigger but lighter and has better handling and neater body control at high speeds, well, at very high speeds. If you just pootle to the shops or hair salon or have a bit of a blast on public roads you may not feel any difference.

In the hands of Porsche’s Timo Kluck, it is 14 seconds quicker round the Nurburgring than the last Carrera S, in 7 min 40 secs. The dynamic chassis control system, fitted for the first time in a 911, contributed four or five seconds saved. This is an optional extra and reduces body roll and keeps the wheels in better contact with the road.

A wet track, even with the expert instructor driving me, was no place to sense the differences. However, it is noisier inside because a resonator pipe has been fitted to bring a throatier noise into the cabin – after comment by existing 911 customers that they wanted more roar for their bucks.

The 911 per se began in 1963 with the model called the 901. The 2012 version is the fourth all-new model (defined by having a new wheelbase) and the seventh generation. Throughout, it has retained a flat-six engine mounted over and driving the rear wheels, under a distinctive two-door coupé body with a front luggage boot.

This time, the 911 uses aluminium for just under half the body mass, with a 13 per cent weight saving on the bodyshell and a 25 per cent gain in torsional stiffness.

A larger rear wing generates downforce for the first time in the standard Carrera model. The wing adjusts to the airflow created by the sunroof, usefully a third bigger, which slides back over the roof – thus not impinging on interior headroom.

The Carrera’s new 3.4 litre engine achieves the same torque but delivers five more horse power than the old 3.6, with gains in miles per gallon and reductions in CO2. The manual gearbox is the world’s first seven speeder. When fitted with Porsche’s latest PDK twin-clutch automatic gearbox it achieves an official 34.4mpg, and with 194g/km of CO2 is the first Porsche to dip under the 200g mark. It runs on 19 inch wheels.

The Carrera S engine remains at 3.8 litres but has an additional 15hp to reach 394bhp and a similar gain in torque. It also has better mpg and CO2 figures, with the PDK gearbox rated at 32.5mpg and the CO2 figure down 35g/km to 205g/km – better than the previous 3.6 Carrera. It has 20-inch wheels.

Acceleration is marginally quicker on both models, with a manual Carrera reaching 62mph in 4.8 seconds and 179mph. Fitted with the PDK gearbox the 0-62mph time is 4.6 seconds and with the rapid start Sport Chrono pack just 4.4 seconds. The comparative figures for the Carrera S are 4.5, 4.3 and 4.1 seconds and a max of 188mph. The purchase price is £71,449 for the Carrera with manual gears and £81,242 for the Carrera S.

The improved PDK gearbox is smoother setting off, and now has a coasting function. It is £2,387. The Sport Chrono pack, which includes dynamic engine mounts to stop the engine moving when being hammered round a race track, is £1,376. A telephone module costs an extra £558.

My Carrera S test car for the session was endowed with several other options. Parking sensors front and rear cost £639; a sports exhaust (more noise when required) was £1,772. Cruise control added £267. The aqua blue metallic paint was £801 and a sunroof £1,149.

The cabin now looks better, with hints of the Panamera, and is more ergonomic in parts.

It remains a cosy 2+2, with the two rear seats only suitable for dogs, small children and any shopping you don’t put in the forward boot.

The seven speed manual gearbox has decent shifting. Seventh gear gives 70mph at 2,000 rpm, so is not all that lazy and pulls well at lower speeds.

The new Carrera models are on sale now, joined by the cabriolet on March 3. The Carrera 4, GTS and Turbo models of the outgoing series remain on sale this year and are expected to be replaced in 18 to 24 months. «