Autoblog, lucky bunch that they are, reviewed the 2011 Porsche Cayenne S and had this to say:
With the Cayenne I sampled only the V8, but drove a Touareg with the V6 in 280-horsepoweer tune immediately beforehand. While the V8 is quicker and more sonorous than the V6, it doesn’t transform the Cayenne like it does the Panamera. Blame two factors. First, while the 4,553-pound 2011 Cayenne S is, commendably, 400 pounds lighter than the 2010 and 740 pounds lighter than the similarly-dimensioned BMW X5 xDrive50i, it remains ten percent heavier than the Panamera.
Porsche has some of the world’s best engineers, but even they can’t defy the laws of physics. The Cayenne is a large, heavy vehicle, even after the 400 lb diet it received this year. If you’re going to spend your hard-earned money on a Cayenne, save a bit longer and get the Turbo. You won’t regret it.
Read more about the 2011 Porsche Cayenne.