The 997 was an evolution of the preceding 996, with significant changes being made to the interior and exterior styling (the most notable of these being the replacement of the "fried egg" headlamps used in the 996 with the classic "bug eye" units).

Larger 18-inch wheels were fitted as standard, and other engineering changes include slightly increased power; however, the car is technically very similar to its predecessor despite many revisions.

During 2009, Porsche refreshed the 997 lineup, making styling changes, incorporating a new engine with direct injection, and introducing the company's new "PDK" dual clutch transmission.

As a result, the refreshed 997 models were faster, lighter, and more fuel efficient than the outgoing versions, with improved handling.

In the case of the 997 Turbo, a comprehensively re-tuned all wheel drive system with ”torque vectoring" as an option was also a part of the upgrades package; in an October 2009 preliminary review, Car and Driver magazine estimated that when equipped with the PDK transmission, the updated Turbo should be capable of accelerating from 0–97 km/h (0–60 mph) in three seconds.

Porsche applied the logic that if you started with engineering challenges more unique to the cabriolet (for example, chassis stiffness), the coupé version would simply be more rigid.

Even the rear wing rises slightly higher on the cabriolets to compensate for differences in drag over the canvas top versus the smoother coupé shape.

[5][6] The vehicle included an Azurro California-colour scheme (similar to the colour found on the Porsche 356), a vehicle identification number (VIN) which ended with the production number and special commemorative badging and door sills, Sport Chrono Package Plus system, and optional Porsche Ceramic Composite Brakes.

At any speed, the roof can be opened where it drops down 25 mm and slides a metre back underneath the rear window.

Large air vents fore and aft of the rear wheels provide other obvious visual cues of the Turbo model.

It is capable of similar top speeds and acceleration to the standard Porsche 997 turbo coupé, a notable feat due to the typical problems associated with convertible variants of hardtop coupés, such as the poor aerodynamics of a soft top, a lack of torsional rigidity, and the consequential weight increase from structural members.

Despite the power hike, Porsche claims fuel consumption at full throttle is improved by 15 percent compared with the 997 Turbo.

[citation needed] The GT3's body work includes a special front bumper which increases cooling for the front-mounted radiators as well as a split spoiler at the rear.

The special GT3 RS model[12] came without many of the luxuries typically found in a Carrera to focus more on track-orientated driving (although the car is still road-legal).

The RS trim was also available with a full roll cage and carbon fibre seats along with a large fixed rear wing to add to the race-car-for-the-road feel.

It received a completely new 6-cylinder, 3.8 litre boxer engine generating a maximum power output of 500 PS (368 kW; 493 bhp) and 651 N⋅m (480 lb⋅ft) of torque (700 N⋅m (516 lb⋅ft) with overboost) using revised BorgWarner variable turbine geometry (VTG) turbochargers.

The model was also available with optional Porsche Torque Vectoring (PTV), which brakes the inner rear wheel to provide turning-torque through a curve reducing initial under steer.

[21][22] The engine had revised intake valve timing and a new carbon fibre airbox installed to achieve this feat.

[20] The car now featured vents between the tail lights, a larger rear wing with "3.8" lettering on either side of the wing to denote the increase in engine displacement, forged pistons, lightweight valves and hollow camshafts in order to make the engine light weight, a special 6-speed manual transmission was the only transmission option with shorter gear ratios in order to feed optimum power to the rear wheels.

Features included titanium double exhaust pipes, carbon fibre rear spoiler lip (Gurney flap) and rear lid ram air scoop, carbon fibre front above bumper air outlet and rear-view mirrors, aluminium 19in forged alloy wheels made specifically for the car with central locking nuts.

It includes a 44 mm (1.7 in) wider rear body, 15 mm (0.59 in) lower front spoiler, 1.70 m (67 in) rear wing (from the 911 GT3 Cup S race car), LED taillights, a racing exhaust system with a fully controlled catalytic converter (from Porsche Mobil1 Supercup cars), Porsche Ceramic Composite Brakes.

The engine is rated at 408 PS (300 kW; 402 bhp) and features a newly developed resonance intake manifold with 6 vacuum-controlled switching flaps.

It includes a 6-speed manual transmission, double-dome roof (informally called double bubble roof), 44 mm (1.7 in) wider rear fenders, SportDesign front apron with a front spoiler and a fixed 'duck tail' rear wing (similar to the one found on the Carrera RS 2.7), Porsche Ceramic Composite Braking system (PCCB), 20 mm (0.8 in) lower PASM sports suspension, mechanical rear axle differential, 19-inch black Fuchs wheels, Porsche Exclusive woven leather seats and door panels, dashboard with Espresso Nature natural leather upholstery, and a specially developed Sport Classic Grey body colour.

The 3.6 litre twin-turbocharged Flat-6 engine in the GT2 RS develops 620 PS (612 bhp; 456 kW) and 700 N⋅m (516 lb⋅ft) of torque and weighs 70 kg (154 lb) less than the outgoing GT2.

When the dust settled, Porsche claimed that test driver Timo Kluck had supposedly eclipsed that target by nine seconds.

All GTS vehicles came standard with center lock wheels, Alcantara interior and other optional extras such as Porsche Sports Exhaust and PASM.

The Speedster featured a windscreen 70 mm (2.8 in) shorter than the standard 997 cabriolet while maintaining the same rake angle along with a familiar hump on the rear section to store the soft top.

The hoods were sold to raise funds for CITYarts, a New York City-based organization whose mission is to bring children in contact with public artists.

This results in wide areas of the cylinder walls having deep scratches or gouges with similar damage to the pistons.

Porsche used a larger, non-serviceable IMS bearing and these engines also received an updated PTFE rear main seal.