Porsche has topped its Cayman and Boxster line-ups with new GTS models. The Cayman GTS and Boxster GTS get more power and performance, revised styling and dynamic changes over the Cayman S and Boxster S models on which they are based.

Each is equipped with a 3.4-litre flat-six engine that now complies with the more stringent Euro 6 emissions regulations. They also have 15bhp more than the S variants, so the Cayman GTS produces 335bhp and the Boxster GTS 325bhp. Torque is also slightly increased, by 0.96kgm in each car, giving 38.71kgm for the Cayman and 37.60kgm for the Boxster.

A six-speed manual gearbox is standard on each car, with a seven-speed dual-clutch auto optional. Fitted with the auto, the Cayman GTS can crack 0-100kph in 4.6sec and the Boxster GTS takes 4.7sec. Top speed is higher in the manual-equipped cars, the Cayman GTS capable of 284kph and the Boxster GTS of 281kph.

A host of dynamic upgrades and packages feature as standard on the new models. These include the Sport Chrono package, which sharpens vehicle responses, and the Porsche Active Suspension Management system (PASM) that brings a lowered suspension and electronically controlled adaptive dampers.

The two-seat, rear-drive Cayman GTS and Boxster GTS are distinguished from S models by their revised front and rear bumpers, blackened bi-xenon lights and 20-inch Carrera S alloy wheels shod with 235/35 tyres at the front and 265/35 tyres at the rear.

Inside, the GTS models get sports seats and a leather interior with Alcantara trim. Sales of the pair are set to get under way in May. Both cars will make their public debut at the Beijing motor show next month.