Here is a related thread:
http://986forum.com/forums/general-discussions/30561-rpms-mpg.html#post260273

98 2.5 manual - average 21mpg 50/50 city/hwy with 93 oct Shell
01 3.0 v6 Avalon - averaged 23-24mpg on same route with 87 oct whatever

Overall I'm happy, considering the Avalon only got 15% better but was 100% less fun.

Avalon I drove like grandpa since I had a trip computer and that 3.0 had zero acceleration it wasn't fun to push hard

De=Snorkled 99 2.5L I get 21mpg combined up to 27mpg Highway at 70mph on 93 octane.

I don't know. I don't care. This is not a MPG vehicle. I someone is concerned about MPG buy a Prius or Cruze. I only care about MPH.

Boxster

Boxster S

I generally drive sanely and I get 22 MPG combined (over the last four months and 4,000 miles) in my '99 manual. I've had as low as 18 and as high as 26.

MPH? Perhaps also the wrong car for you. ;) G's on a skid pad? Now we're talking! :D

HWY traveling I flucuate between 35 to 41 mpg, and in town 24 to 29 mpg. Highway travel is usually a steady speed at or near 75. Step off the highway or mix it up and the mileage drops by about 20%

Wow, Eric G. You sure you're driving a Boxster? ;)

MPH? Gotta be kidding. Box has plenty.

As my 22 year old daughter says to me, "if you drive a Porsche, you should not even think about gas mileage!":dance:

She is driven, but she is also sitting with 89K on her now and I have on order new struts, front wheel bearings, IMS, RMS, and front engine mount. No running issues, rather I am just being careful with her till I am totally comfortable with her ability to match up with my intentions.

The IMS is not going out rather I am waiting till Saturday as we are having a guest engineer attend the monthly coffee meeting our PCA region has and he is bringing an Industrial Vibration Monitoring meters and analyzers. He efforts have lead to a system he built for identifying Boxster, 996 and 997 IMS boogieman.

Once all this work is done and I am happy with the results, its off to the Ridge track and I am fully confident that my MPG will come more in line with the figures above!:cheers:

2001 S - Just got 28 MPG on a 370 mile highway trip.

I was able to drive just over 400 miles on one tank of gas.
Calculated to 29mpg. Mostly highway miles. Base boxster. Average speed of 70mph.

I'd like to direct you to the ---> ;)