GTS versions of the convertible and coupe duo head to the top of the respective line-ups and fit a tuned version of the S models' 3.4-litre six-cylinder engine behind the two seats to lift power by 11kW to 243kW (Boxster) and 250kW (Cayman).
With a Sports Chrono package that quickens the cars' responses fitted as standard rather than optional, the Porsche Boxster GTS and Cayman GTS take another tenth of a second off the fastest 0-100km/h acceleration times of the Boxster S and Cayman S - to 4.7 and 4.6 seconds respectively with an optional PDK gearbox.
There's no penalty at the bowser, either, with both models boasting the same official fuel consumption as the S models - 9.0 litres per 100km in six-speed manual guise, or 8.2L/100km with the seven-speed 'PDK' dual-clutch auto.
It means the Porsche Cayman GTS is also a tenth quicker than the coupe's former flagship, the R, while also being more fuel efficient.
Porsche Active Suspension Management (PASM) is also included to bring a lowered, electronically adjustable suspension designed to make the GTS models the sharpest drives of the Boxster and Cayman models.
Picking the GTS versions from other Boxsters and Caymans is by modified front and rear bumpers, blackened bi-xenon headlights, and 20-inch Carrera S alloy wheels wrapped in 235/35 rubber up front and 265/35 rubber at the rear.
The standard leather cabin and seats also features Alcantara trim that has come to mark the interiors of GTS models.
Porsche has been spreading the GTS badge throughout its range since reintroducing it in 2007, on the Cayenne.
The Porsche Boxster GTS and Cayman GTS go on sale in Australia in May, with the convertible priced from $146,000 and the coupe from $161,400. That's respective premiums of $19,500 and $21,500 over the S models.
The Cayman range may not be finished with the GTS. Porsche recently told CarAdvice a GT3 version, which would be expected to copy the weight-reduction focus of the 911 GT3, is being considered.