When I brought my then stock 87 cabriolet from chicago - I averaged 26mpg for the entire trip (72 mph average, 1100 miles.) One tank close to 30mpg. one tank at 21 mpg - but I averaged close to 94mph for that tank ;)

With the 3.4 - and 993ss cams - I averaged 17mpg on the way to daytona and RRIII - but it's worth it...

Finally got to take a long trip (260 miles) and check my 3.2 mileage.
The car is totally stock, i.e. no CAT bypass, original muffler, and stock chip,
and with speed between 60-70 MPH the car got 31 miles/gal.

wow, I only get 22+/- (90% SCal freeway) and I thought that is really good.

The problem is with SCal freeway. It's all that traffic you're sitting in!

I think the fuel consumption may be higher on the newer fuel (see old thread below)

The jury's still out for me, but I recently got mid 20-ish mpg on a trip that I usually get low 30ish mpg on.

Has anyone else noticed their fuel mileage getting worse?

http://forums.pelicanparts.com/porsche-911-technical-forum/302832-30-mpg-carrera-3-2-possible.html