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Hi all, new owner of a 99 996.

As I have been getting used to the squeaks I can't help but notice I am at the gas pump every couple days.

On the tank I have now, I have about 100 miles so far, with the tank showing about half left.

How much does the A/C hurt the mileage? I understand it will hurt some, but this is crazy.

And, if the little snowflake is not showing on the controls, does that mean the compressor is not on?

Is this normal?

I used to own a 64 cadillac, and she didn't seem as thirsty as this girl.

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With the price of gas going thru the roof I thought I would try driving relatively conservatively and see what kind of mileage I could get. On my '99 Cab mixed hwy/city I got just over 25 average and 352 on a tank before I filled up. This did include a couple of blasts full throttle entering the freeway and a few runs into the triple digits as is required when owning a car like this. I also used the AC some and it doesn't seem to affect mileage much, but the top down at speed probably does. Pretty careless driving and aggressive use of the throttle net me about 18-19 mpg average.

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I get about 17 city, 27 highway, and 8 on tracks. However, I do about 110 miles a week too, just going to work, and the tank needle shows 1/2. But when I fill it will only take about 6 gallons. I do not think the tank meausure is necessarily linear. So after filling the tank, drive the 100 miles, then fill again and record the gallons. then divide 100/gallons to get a more accurate read.

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I am getting about 14 mpg on city, and 28 on the highway. Keep using the car until you get more miles in the tank. Even though I had to replace the fuel pump just a few months ago and had the fuel gauge re calibrated, the first quarter of tank gets "consumed" (as per the fuel gauge) in 30 miles or so. Once you reach the halfway mark, it will take a lot more miles before you see the needle move. As a note, I learned that in order to be sure that there is no fuel left in the tank, the needle has to fall below the low level fuel light. I only did this once as the tech told me I had to nearly run it empty so they could properly calibrate the gauge (requires a specific amount of fuel in the tank to do so).

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13.8 MPG on 02 C4 Cabrio. I've had cars with twice the HP and double the MPG. With the other reports I've read on mileage, Porsche should be ashamed (or at least make these things put out 800 HP where it should be for 13.8 MPG).

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I drive the car 6 miles to work and back for a total of about 12 miles. Start-up uses quite a bit of fuel. If all I do is drive the car to work and back, I get about 15 mpg, with two full throttle bursts per day (why else have the car?). Those that quote higher numbers for mixed driving are driving the car further distances and for longer stretches between stops. I live in the city and come to a complete standstill at least three to four times on the way to work which reduces fuel economy. I have a 5000 lb. Dodge Durango SUV with 335 horsepower that get the same mileage. Remember, in 1999, when my Porsche was built, oil was $11 per barrel, now it's $65. Porsche didn't really care about fuel economy. I'm sure that is changing.

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I just got back from a 376 mile run through 2.5 hours of the God awful San Francisco stop/go traffic, then up into the Gold Country mountains for an overnight visit with friends, then a very spirited drive back thru the mountains home....and the entire trip recorded 20.5 miles per gallon....inclusive of all the stop and go and freeway to mountains trip. I was pretty dogone pleased with that sort of average considering the conditions under which I drove.

I have a 99 996 and recently installed the RSS plenum. I'm not saying the plenum had anything to do with that...just info.

Edited by Chuck Jones
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Well, I have tried the method suggested to calculate MPG.. .and this last tank I did about 17.5mpg.

This is 50/50 highway/street.

So, not quite as bad as I thought, and I am still not turning down any available high speed runs... so should get better as I mature.

Also, anyone know if the A/C has a huge difference? or just a few percent?

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The smaller tanks make you feel like your mileage sucks as you fill up more often. I get 18.4 city/hwy "TOP DOWN" in the 99' 996 6 speed cab that I just turned 19,xxx miles. This is a great auomobile and a blast to drive.

Viper SRT-10 - 8.8 MPG "It is a REAL FAST 8.8 MPG though"

CLK55 Cab. - 17.6 MPG wifes daily driver

BMW 760LI - 17.4 MPG my daily driver

Hummer H2 - 10.2 MPG

Prowler - 20.4 MPG

68 Camaro R/S Z-28 - 13 MPG

23 T-Bucket - 5 MPG 109 octane required 6 bucks a gallon

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Given the traffic in and around the city, sometimes it feels I'm getting 0 mpg because the kid ain't moving. But, generally, it seems like I'm getting around 18-20 mpg combined driving. If I just drive 60mph in 6th gear on a highway, I get north of 25mpg, but who has the patience for that (after break-in, that is).

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Don't necessarily trust the trip computer. Mine is optimistic by 2 full MPG (15.8 / 13.8 is a significant 15% high). Set your trip odo and get fuel added for a few fillups. I now ignore that and use the trip computer because it's too depressing to admit I'm getting less than 14 MPG from a 6 cylinder.

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For an '03 996 Cab manual trans, mixed driving with more highway, I generally get about 24-26mpg; mixed driving with more city miles, closer to 22. Last weekend drove 75 miles to another town. Set the cruise control at 63 and got 30pmg one way, 29mpg coming back (based on calculations, not just the computer). A day at PCA Drivers Skills was closer to 15mpg. Am quite pleased with the mileage.

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