Is this the Prius forum?

 

Hahaha! Exactly

 

I don't worry about the gas mileage in the 911. That said, I certainly keep an eye on it as a possible indicator of maintenance issues.

On an average tank, I get between 18-20 mpg, more on longer highway trips and much, much less on PCA barbeque runs, mountain tours, and occasional excursions to my favorite roads.

 

if the OP is getting 180 miles out of a full tank to empty, and you are not flogging it no stop, something is wrong.

All my driving is stop and go city style and I'm never shifting before 4 grand. I get 260 miles out of a tank.

 

Thanks for the replies guys!

Just to clarify, like you guys, I don't care much about the money for fuel, it's the fact that the car needs a refuel every other day if I take it to work! It's only just occurred to me this fuel consumption problem as I usually go to work by a E250 and it's gone in for repairs (the missus, the iPhone and a post in the car park). I am also worried that there's some problem with the car that I or the dealer didn't pick up.

Just put in an order for the durametric cable

 

Get your alignment and suspension checked. I had horrific MPG and a floating front end at high speed when I first purchased my car, and they finally found a rear trailing arm that needed to be replaced and a 4 wheel alignment as it was out of spec. My MPG jumped from 12 to 14 on the highway to 29 to 31 now in highway driving. I get less in the city, probably around 18 to 22 mpg if I drive it gently. Also try a few bottles of Techron fuel system concentrate.

 

Jim,

Do you get that figure from a full tank till the fuel light comes on? I just brimmed it last night before the fuel light came on, but in any event less than a quarter tank, and it did 180miles...

 

Thanks for the suggestion! Will get a bottle of Techron plus tomorrow and will book it in for an alignment. It does track straight and feel planted though but will get it done!

As for wheels I am running stock C4S wheels ie those turbo looking ones with dealer supplied S02A tires

 

Differences in driving really influence fuel mileage thus fuel mileage varies from driver to driver.

First are you sure the filling of the tank is right? Sometimes the nozzle shuts off early. I have found for the most consistent fill ups to turn the nozzle handle nearly upside down then let the nozzle shut off on its own.

Next the slight stutter could be important. I take it the CEL is dark? Does the CEL come on when you first turn the key to the on position?

The car is new to you. Do you know the previous owner used good gasoline?

You might consider running a bottle or two of Techron through the tank to remove fuel system/engine deposits. Follow directions and I prefer to change the oil/filter after the last tank with Techron gets low enough to prompt me to add fuel, which is generally about a 1/4 tank of fuel remaining.

Also, these engines benefit from a good run. No need to go out and behave like a rally driver on meth but a good highway jaunt of 30+ miles can have the engine perk up noticeably. 'course, before you head out you want to make sure there is nothing else that can account for the behavior and poor fuel mileage.

About fuel: Be sure to use the proper grade of fuel, octane grade, and buy top tier gasoline and buy from a busy station. Supermarket station gasoline varies in quality is what an Evo (UK car mag) fuel test a few years found and even gasoline at any station can vary in quality if the fuel is old and thus stale. High octane fuels go stale quick hence the advise to buy from a busy station.

Anyhow, the stutter could be an early warning of a failing AOS. My 02 Boxster exhibited a mild hesitation when moving off from a stop and this eventually proved to be due to the AOS. You will need to consult with an experienced Porsche shop to have this possibility looked into.

Things you can do to help fuel economy. Be sure the engine intake air filter is not too dirty.

Check the tire pressures and be sure they are set right. When cold weather hits tire pressures plummet and they need to be adjusted.

 

I get 28 mpg on the freeway if I try my hardest to achieve maximum mpg (easy on acceleration, careful braking, etc.). Of course, other than to see what was the best mileage I could obtain, I rarely drive like that. Even so, it averages to about 23 mpg of combined city/hwy driving, with plenty of "spirited" driving per tank full. Per the computer, I averaged 14.7 mpg on the track.

I also have learned to fill it with the nozzle upside down like Macster mentions. If I don't, I can never be sure if it's completely full until it's overfilling onto the ground. The automatic shut-offs on the nozzles are a very unreliable way to know when full, but they seem to work way better when upside down for some reason that I assume is related to the shape of the bend in the fuel filler pipe.

 

The CEL does light up upon first turn and goes off after the car is started. I've actually got the car for quite a while, from a friend and his wife used to use it.

When I cleaned the MAF today I also disconnected the battery as per research on here. Hope it does get better.

Speaking of brimming it, I only get about 30-40miles out of the first quarter. Maybe I am not brimming it enough then?

 

You want to see bad mileage? Buy a V8 Cayenne!

 

^^^

Yea!

 

No kiddin ...

 

Same again.....I only get 30-40 miles out of the first quarter tank....