It is normal to go from full tank to 3/4 tank at around 65 driven miles?

 

Thats a loaded question. Were you driving aggressivly or taking it easy?

 

mixed driving... actually, it's at 59 miles and half a tank...

 

I get about 29mpg on the highway when cruising between 75 and 80mph.

The lowest I have seen is about 17mpg when really driving the **** out of the car but general lead footed city driving gets me about 18.

 

Possibilities:

Your gas tank might need recalibration.

If you drive a C4 and it got below 1/4 tank read the owners manual about why not to do this.

Your fuel level sender could be on it's way out.

Your not able to fill your tank due to bad tank vent valve.

 

Fill her up and see what mpg you are getting..

 

Reset your trip counter at fill up and then measure your gas mileage at your next fill up... I average 16.2 MPG per tank but I also just got the car two weeks ago... it's steadily been going up each tank. That's the only real way to tell. I wouldn't trust the gauge that accurately to measure gas mileage.

 

thanks, yea, will do... i just got the car myself too and only filled her up once..

 

I have an iPhone app I love, I don't know if they have it for other smartphone OS's or not, but it's called gascubby. I'm sure there are similar applications for other phones, but basically you just input your mileage and gas and it'll calculate your MPG and keep track of what you've spent, etc. Good to have if you're the type who likes to keep records.

 

depends what kind of city driving. i live in a downtown city core. most trips are 2-3 miles. lots and lots of red lights, constantly accelerating then right on the brakes. i get about 11mpg, but i drive the car

redline once a day keeps the mechanic away!!

 

Hey PK, same here... Work is less than 3 miles away each way for me... Count lunch, maybe an extra 2 miles, totaling less than 10 miles a day... I will check out some apps from the marketplace of android. Thanks Ky!

 

That kind of usage not only results in poor gas mileage it subjects the engine oil to the build up of water and unburned fuel.

And since the car is used for short trips the engine oil never gets hot enough long enough to boil the fuel and water out of the oil.

Skip the Android apps and invest your money in to more frequent oil/filter services for your car's engine.

Sincerely,

Macster.

 

hey macster! cheers for the tip, it's good for new owners. i've had my 911 for 3 years and know of short trips spoiling the oil faster. my temp gauge usually gets to 180 before i shut 'er down.

regardless i change my oil every 6000kms with Lubro Moly (made in Germany) 5w-40

 

My car does very good on the freeway >26mpg...but does poorly on my regular short trips. Can't keep my foot out of it. After warm up I like to see the tach hit 6000 rpm

 

I would bet you didn't get a full tank of gas. Some of the fuel pumps with the vapor catcher nozzels will not give a full tank when they auto shut off.