What's all this about?

Porsche has made the 911 Turbo and Turbo S models even quicker than before. Probably the last thing they needed, but hey - who are we to complain?

Driven by the move to all-turbo engines for rest of the 991.2 range?

Probably, although Porsche always keeps innovating throughout a model's lifetime. The Turbo and Turbo S have been updated in a number of ways, not just power.

How else have they been revised?

There's the new exterior styling as seen on the rest of the latest 911s, here adorned by Turbo-specific addenda like 20-inch alloys, new LED headlights and a revised rear end with new exhaust pipes and a redesigned engine cover. Inside are the latest Porsche Communication Management satnav/infotainment system and a 360mm GT sport steering wheel that takes it inspiration from the 918 Spyder's. This features a rotary Mode Switch and a Sport Response button, which can either sharpen up the whole car's attributes in each of the modes or, in the case of Sport Response, simply pre-condition the engine and transmission for maximum power for 20 seconds. This latter feature is useful for near-the-knuckle overtakes and a countdown timer in the dash tells you how much time of Sport Response remains.

Any other dynamic goodies?

A new, more lenient Sport Mode in the Porsche Stability Management (PSM) joins the party, while the Turbos get radar-based lane change assist and a front axle lift system that can raise the nose of the car (and its lowly lip spoiler) by 40mm at low speeds. Porsche Active Suspension Management (PASM) is standard on all models and the Turbo S also enjoys Porsche Dynamic Chassis Control (PDCC) and the Porsche Ceramic Composite Brakes (PCCB). Then there's 'dynamic boost function'.

What now?

DBF maintains the turbos' charge pressure during load changes (i.e., when you have a slight lift on the throttle) by interrupting the fuel injection alone - the throttle valve remains open. That means that when you ask for power again, the engine responds instantaneously.

OK, it's all sounding good. So tell me about the power gains.

It's what, on the face of it, looks like an incremental 20hp increase on both models. That means the Turbo now has 540hp, while the Turbo S totes 580hp. These uplifts are achieved via different means - on the Turbo, it's done by modified inlet ports in the cylinder head, new injection nozzles and higher fuel pressure; over on the Turbo S, a pair of new variable geometry turbochargers with larger compressors are responsible. Whatever; the results are startling.

How quick are we talking?

Mind-blowingly rapid, and intriguingly the S is (to the best of our knowledge) Porsche's first road-going 911 that's capable of more than 200mph. So the Turbo now does 0-62mph in 3.0 seconds flat and runs on to 198mph where permitted (that's 1mph quicker than the pre-facelift, 560hp Turbo S), while there's an additional 8mph for the new Turbo S when going full tilt - meaning this is a Porsche 911 capable of 205mph. The 0-62mph time, by the way, is a ripping 2.9 seconds.

Can the 911 Turbos be had as hard-tops only?

No, either the Turbo or the Turbo S can be Coupés or Cabriolets. According to Porsche, they'll even return 31mpg with a fixed roof or 30.4mpg as open-tops, which is about 2mpg model-for-model better than their predecessors.

And when are these powerhouses joining the range?

Following a debut at the North American International Auto Show (NAIAS) in Detroit in January, first deliveries of the new Turbos will be later that month, although you can order the machines now. The Coupé Turbo and Turbo S cars are £126,925 and £145,773 respectively, while the Cabrios are nearly nine grand more expensive than their brethren - at £135,766 for the Turbo and £154,614 for the Turbo S.