The only visual clue that differentiates the 2006 Porsche Cayenne Turbo S from the regular Turbo is the silver “S” on the rear liftgate. Mechanically, there are also few differences between the 4.5-liter V8 in the Turbo and same engine in the Turbo S – just a few tweaks to the turbocharging system – but those differences are significant. Horsepower jumps from 450 to 520 ponies at 5,500 rpm, and torque surges 73 pound-feet to 530 lb.-ft. at 2,750 rpm. The changes are good enough to affect a 0.4 second improvement in the 0-60 acceleration time to 4.8 seconds and to achieve a 3 mph top speed increase to 168 mph.