"...the new Mk3 will be more strongly differentiated from twin-under-the-skin 911, with a flat-four powerplant and a raft of technical changes, say our sources in Zuffenhausen.

The replacements for Boxster (981) and 911 (991) were signed off by the old regime, so once again the two cars share elements of their platform and componentry. While the 911 remains the high-end model with a power output of up to 600bhp and a strong emphasis on new six-cylinder boxer engines, Boxster and Cayman will eventually also be available with downsized four-cylinder boxer units.

Project 981: the next Boxster in detail

The 981 is not an evolution of the current model but an all-new vehicle. Its cab-forward design has much crisper and sportier proportions, but is still easily recognised as a Boxster. The new look is reflected by a shift in the Boxster's dimensions. The wheelbase grows 60mm, overall length is up 37mm, overall height drops by 10mm, and the front overhang is trimmed by 25mm. Inside the two-seater's cabin, legroom improves by 18mm.

Although the new model is slightly bigger and significantly better equipped, the weight will come down by 15kgs to 1320 kilos for the standard Boxster and to 1340 kilos for the Boxster S. Bespoke doors, tailormade lights, jazzier front and rear ends, restyled 18in wheels (19inchers for the S), a more steeply raked windscreen and a new version of the Boxster's distinctive side air intakes help differentiate the Boxster from its predecessor, and the 911.

The interior, too, has been redesigned from scratch, featuring a relatively wide, rising console and centre stack, higher-class surfaces and the large touchscreen monitor we know from Panamera and Cayenne.

Dynamic tweaks for the new Boxster

The longer wheelbase is said to improve the ride comfort as well as the directional stability. The McPherson strut front and the multilink rear suspension have been re-engineered for better handling and reduced noise. Also new are larger-diameter 330mm front and rear brakes borrowed from the next Carrera 2 and an electrically-operated parking brake.

Among the most interesting options are the adaptive suspension management (PASM) which extends to the steering and the dual-clutch transmission, and torque vectoring (PTV) and radar cruise control which bode well for the Boxster retaining its dynamic edge whilst offering a level of comfortable cruising to match rivals like the BMW Z4 and Mercedes SLK.

Powerplants for the next Boxster:

While the output of the 2.7-litre engine goes up to 265bhp and 280Nm, the new 3.4-litre S version delivers 315bhp and 266 lb/ft. When fitted with PDK, the lesser model will accelerate in 5.7sec from 0-62mph and top an unchanged 164mph. The Boxster S does the sprint in 4.9sec; its maximum speed is 171mph, the same as before.

When the first round of cosmetic and engineering modifications is due in 2015, Porsche will introduce a new four-cylinder boxer engine, sources claim. The Boxster/Cayman is believed to feature the bigger-bore 2.5-litre twin-turbo version which comes in various performance stages, delivering up to 360bhp and 347lb ft. If marketing agrees, the entire range could eventually switch to the new drivetrain. There is even room for a hybrid pack which will be incorprated in the PDK transmission housing. Although the customers may not yet be ready for a diesel-engined Boxster/Cayman, converting the new boxer to TDI technology is said to be difficult but feasible too.

When do we see the new Boxster?

While the new 911 is expected to debut at the 2011 Frankfurt Show, the next Boxster is scheduled to be unveiled in Detroit in January 2012."