Second tank, 17mpg from ~ 105mi city, ~50 fwy.
I need to check the air filter, and track the fuel trims.

I have driven 17573 miles in just over 3 years. I am at 20.66 Avg MPG. Keep your tires at proper pressures and stay up on the maintenance. I think you are in the ballpark. How spirited do you drive? I have had tanks that measured low at +/-16 and high at just over 23. Safe travels.

My 2000S 6sp would get 17-18 around town and 28 on the highway.

Tailwind, Sounds about right, I have an 01S, I get 15-18 in city driving with really bad traffic and have gotten 25 on highway to Reno.

Second tank, 17mpg from ~ 105mi city, ~50 fwy.

I also had this question, and found this thread:

http://986forum.com/forums/boxster-general-discussions/68532-how-many-miles-tank-typically.html

A lot of perspective from forum members.

I get about 16-18 MPG city and if I'm lucky 20-22 Hiway; same as my 5,115 pound Toyota Landcruiser

Hm,

i have to convert from Liter / 100 Km to mpg.

My average consumption is around 10 Liter / 100 Km, which converts to 24 mpg.

Lowest i got was around 8.5 Liter / 100 Km, which converts to 28 mpg.

If i push the car hard, it's around 12 Liter / 100 Km, which converts to 19.5 mpg.

On the Autobahn at higher speeds above 200 Km/h and more up to vmax it was around 15 Liter / 100 Km, which converts to 16 mpg.

Don't know what you do to get such bad mpgs in general.

It ain't a Prius, don't drive it that way. Once warm, an "Italian tuneup" every once in a while.

Of course, how fresh are the coil packs and plugs?

It seems to me first thing is to verify your calculation. Run through a full tank and I would double check the miles driven with a GPS to make sure the odometer is within reasonable limits.

Just getting on the freeway, the reserve light came on. After a 35 mile round trip, the needle was half way between Empty and Positively. 14 gal fill with 276 on the Odo = 19.8MPG mixed driving, more freeway this tank.