In classic enthusiast baiting tradition, Porsche’s released images and details of its new 911.Due for public debut at the Frankfurt auto show in mid-September, the world’s most successful sportscar (and most successful racecar too) gains a host of styling upgrades and has grown in length.The new 911’s rear axle has moved 76mm backwards (elongating the wheelbase by 110mm). This change is sure to benefit both cabin space and high-speed stability but, despite the best efforts of Michael Mauer’s design team, the greater length has not been perfectly harmonised into the classic 911 silhouette.In terms of detailing, Porsche has altered the head and tail lights slightly and embellished the 911’s illumination with new LED graphics.BIGGER, BUT BETTER INSIDEAlthough slightly larger overall, the new 911 is lighter courtesy of a new body that trims mass by 45kg in stock Carrera form, rendering a 1370kg kerb weight. Curiously, Porsche has not chosen to employ contemporary aluminium spaceframe construction methods (as perfected by its VW sibling brand, Audi) or a carbon-fibre monocoque chassis, preferring to continue with its traditional unitary body construction. The blend of steel/aluminium (as opposed to the all steel 911s up to now) is considered optimal for requirements (rigid and light enough) by Porsche’s engineering staff. Usability improves as the 911's nose area luggage capacity increases from 135 to 140 litres and cabin ergonomics gain a cleaner feel with the presence of a push-button parking brake to replace the classic girdle-actuated system.Porsche’s stylish Panamera-sourced centre console (finally) brings the 911's ergonomics to a standard comparable with contemporary performance cars. Traditionalists need not worry - the 911’s tachometer still takes pride of place in the centre of the five-dial instrument stack. IF YOU REALLY LIKE SHIFTING...The water-cooled, flat-six engine line-up is carried over. The familiar 3.6 has, however, been downsized to 3.4 litres, and the "S" configuration 3.8 engine retains its full capacity from the current 911. Optimisation with the aim of lowering emissions (courtesy of advanced direct injection) results in more efficient combustion, benefitting performance too.Porsche’s classic 3.6 flat-six (though shrunken to 3.4-litres) gains 3kW to 257kW, supported by 400Nm. The 3.8-litre powering the Carrera S has been reworked to produce a noteworthy improvement of 11kW over the current model, peaking at 294kW. Torque swells to 440Nm from the current car’s 420Nm.Porsche’s best-kept engineering secret in many a year debuts with the 991 too: one of the most elaborate dog-leg H-gate transmission systems yet offered in a road car, featuring seven gears. The seven-speed manual transmission is a world first and will undoubtedly thrill enthusiast drivers who prefer to do their own engine-speed rev-matching when downshifting. SENSIBLE SUPERCAR: Elongated shape smoothed over by new LED illumination and standard 20-inch wheels… Porsche's more popular (for those drivers who can’t be bothered to do their own rev-matching when downshifting) dual-pedal seven-speed PDK option is carried over from the current range. For the 3.4-litre Carrera Porsche claims benchmark 0-100km/h sprint times of between 4.4- and 4.6 seconds, whilst the 3.8-litre Carrera S is good for either 4.3- or 4.1-seconds when blasting to 100km/h from standstill. The quicker times with both cars are achieved with the PDK transmission option and Sport Chrono engine and drivetrain management package. Stop/start technology and brake energy recuperation features are integrated in the suite of mechanical features to ensure the new 911 returns stellar fuel consumption figures and has as low an emission signature as possible. Claimed combined cycle consumption is remarkably low: 8.2l/100km for the 3.4-litre car and 8.7l/100km for the Carrera S. Shoring up the 911’s fabled agility is a redesigned multi-link rear suspension, an electronically managed locking rear differential and (controversially) a switch to electro-mechanical steering. That last engineering change (adding electronic assistance to the helm) will potentially be the most upsetting to 911 purists...When the Carrera 4S arrives by October 2012 expect it to sport the latest in torque-vectoring technology (enabled by interplay between the all-wheel drive system and individual brake rotor pulse technology) to sharpen up the driving experience even more.The world’s favourite sportcar remains an ode to focused engineering (what else would you expect after 48 years of evolution?) and truth be told: real sportscars are made from steel, not aluminium or plastic, right?