PORSCHE has upgraded the Cayman coupe over the Boxster on which it is based, with a slight boost in performance over its convertible sibling to secure its status as the company’s top mid-engined model.

Previously, the Cayman and Boxster had the same power outputs, but for the 2009 mid-life upgrade of both models launched in Australia this week, the Stuttgart company has placed the coupe up the pecking order by applying modest but significant increases in power and torque over the equivalent Boxster models.

The base Cayman gets 195kW and 300Nm from its new-generation 2.9-litre flat-six engine – 7kW and 10Nm more than the Boxster.

Similar increases have been applied to the Cayman S, which generates 235kW and 370Nm from the otherwise identical direct-injection 3.4-litre unit as the new Boxster S, which is rated at 228kW/360Nm.

Cayman therefore produces 8.3 per cent more power and 9.9 per cent more torque than the superseded 2.7-litre base model while the new Cayman S engine (which is the same capacity as before) is up by 8.3 and 8.8 per cent respectively.

There is also slightly more visual differentiation between the models for 2009 as a result of the Boxster getting aerodynamic diffusers alongside the central exhaust, but not the Cayman.

Cayman shares the Boxster’s other subtle exterior revisions as part of its mid-life makeover, with new two-tube headlights, larger front intakes and round rather than elongated exhaust outlets.

But it is the mechanical package that sets the Cayman apart from the superseded model, highlighted by the all-new engines and also the introduction of Porsche’s new seven-speed (with two overdrive gears) PDK twin-clutch manumatic gearbox, all of which debuted in the 911 range only late last year.

Porsche Cars Australia has priced the PDK competitively at $5500, which is $1500 less than in the 911 and only about $600 more than the old five-speed Tiptronic S it replaces as the automatic option.

It also significantly undercuts BMW’s similar M-DCT unit, which costs $7200.

With the faster-shifting PDK fitted, Cayman accelerates from 0-100km/h in 5.5 seconds while the Cayman S stops the clocks at just 4.9 seconds – half a second faster than before.

Porsche introduced the Cayman to Australia in February 2006 as a new entry level coupe that was based on the Boxster, and therefore had a mid-mounted engine, but which looked more like the rear-engined 911.

Cayman now almost matches the convertible Boxster for sales in Australia and, although Porsche’s market dropped considerably last year, it held up much better than both Boxster and 911.

Like Boxster, Cayman gets more equipment for only small price increases, with both the base and S models gaining rear parking sensors, electrically adjustable seats (with memory on the driver side), Porsche’s latest touchscreen entertainment and navigation screen with a hard-drive, and an audio interface with iPod connectivity and functionality.

Prices for the base model have increased by $600, and by $900 for the Cayman S.

As well as the bigger engine, the Cayman S boasts bigger wheels (one-inch larger diameter bigger and half-inch wider), twin tailpipes and aluminium-coloured instruments and interior features over the base model, but both versions now get the same 318mm front brake rotors.