Poor MPG Cayman S
 

I took delivery of a 2011 Cayman S with 6-sp man in Dec 2010 and presently have 3,600 miles on the odo. I live in a suburban/rural area, so most of my driving is in 4th through 6th gears. I tend to shift around 3,000 RPM and seldom drive aggressively. Why, then, am I averaging only 20 MPG (using 91 octane gasoline)? The tire pressure is correct. My Porsche dealer is stumped.

Sounds like you should be closer to 25mpg. A friend that has an 06 S gets about 22mpg in mixed driving in a city. Do you perhaps not upshift and keep the cruising RPMs above 2500rpms?

I found my Boxster (03S) got better mileage when I tried to keep the revs at 3K and above. I would say it bought me 2-3 mpg. Think I'm getting about 22 around town, as high as 28 highway.