AFTER more than 34 years of air-cooled 911s, the new model is powered by a rear mounted, horizontally opposed, water-cooled six-cylinder engine. Related to the 2.5-litre Boxster, the 3.4-litre 911 develops more power and torque - 221kW (up from 210) at 6800 rpm and 350Nm (up from 330) at 4600 rpm - despite being 213cc smaller than the old air-cooled 3.6. The most powerful Carrera ever, the 911 has shown its quick down the drag strip - independent tests have been a few tenths outside the claimed 5.2 sec for 0-100km/h. Fuel consumption is down 10 percent.