The Boxster S sticks with its 3.4-litre flat-six but gains an extra 4kW, taking its total to 232kW.
Both engines are fitted with stop-start. Performance has taken a small jump.
The Boxster accelerates from 0-100km/h in 5.7 seconds - a 10th of a second faster than the old car - while the Boxster S takes exactly five seconds, an improvement of two tenths.
While the second-generation Boxster, launched in 2004, brought only subtle design changes over the original mid-engined roadster released in 1996, the new model borrows a number of design cues from next year's million-dollar plug-in hybrid 918 Spyder super-roadster.
Most noticeably, while the front half is essentially all 911, the changes include deeply sculpted side air scoops that begin within the shorter and now-concave doors (which are now unique to the Boxster and, like the 911, house the side mirrors) and feed the car's mid-mounted six-cylinder boxer engines via oversized air inlets ahead of the rear wheels.
Also increasing the new aesthetic aggression are new vertically stacked headlight elements, LED daytime-running lamps, a distinctive new integrated rear lip spoiler design that overlaps the tail-lights, an 11mm-lower roof height and larger, more pronounced haunches at both ends.
Porsche says the more masculine design aims to reduce the average Boxster customer age from about 45 while maintaining its attraction to women, who currently account for about 20 per cent of Boxster buyers.
The all-new steel-aluminium hybrid body - a first for the Boxster - also echoed the 911 by delivering weight savings of up to 35kg in the top-shelf Boxster S, as well as increasing torsional stiffness by some 40 per cent.
For the first time, the Boxster was available with 911 technologies including ceramic brakes and Porsche Torque Vectoring, which brakes the inside rear wheel for greater cornering agility, while reworked MacPherson strut front and rear suspension, larger front brakes for the Boxster S and electro-mechanical power steering complete the chassis overhaul.
The new Boxster - which is 32mm longer overall at 4374mm - does not come with the new 911 Cabriolet's folding fabric roof, but instead gets a new magnesium-framed roof structure that can open or close fully automatically in just nine seconds at speeds of up to 50km/h and cuts cabin wind noise at 100km/h by half.