Mpg

[PatrickB]

30 mpg... Yes!
It was on a long distance trip from L.A. area to Reno up Hwy 395 averaging 80-90 mph. This was even before I had the headers on, but had brand new fuel injectors, and a SW chip. You might be in for a pleasant surprise if you have your injectors rebuilt or replaced with new. My MPG improved dramatically after doing so with the addition of a SW Chip!!!

[janz]

Already got the SW chip. Also my mpg doesn't change with the AC on probably because I have all the windows closed and sun roof closed. I agree with going slower on the hiway will increase mpg but I want to get there so I was just wondering if I was missing anything that might help. Seems I have all the bases covered and I'm doing OK on mpg. I had considered a positive forced ram air, using a fan and ducting it to my air cleaner intake but that post seemed to go nowhere. I even have the aero mirrors instead of the flag mirrors to cut down on drag not to mention I think they look better.

[rick-l]

Originally Posted by PatrickB

30 mpg... Yes!
It was on a long distance trip from L.A. area to Reno up Hwy 395 averaging 80-90 mph. This was even before I had the headers on, but had brand new fuel injectors, and a SW chip. You might be in for a pleasant surprise if you have your injectors rebuilt or replaced with new. My MPG improved dramatically after doing so with the addition of a SW Chip!!!

I just find it hard to believe that a car that had an EPA rating of 14 and 24 gets 30 cruising at 90 MPH.
http://www.fueleconomy.gov/FEG/bymake/Porsche1988.shtml

[PatrickB]

The efficiency of the A/F ratios and the fuel injector performance makes this possible. Steve has the magic ratio's set up in his chips for fuel efficiency at cruise. How many miles on your engine? If it has high miles, and you've got the oem injectors, time to have them overhauled!!!!!!! Not only will your engine gain power, it will be far more efficient on the mpg side! ask me how I know....

[kach22i]

How come the top part of the gas tank gets more miles per gallon than the last part? I was heading for 30 mpg, then had to switch to short trips and city driving over the weekend which killed it.

Is it the Reserve part of the dial?
CIS fuel consumption, what is normal?

[GH85Carrera]

I saw 27 MPG on my trip to Parade this year. That was on 100% gasoline. The ethanol blend fuel in that part of the country dropped that a several MPG. On the track for the DE I used 1/2 a tank of fuel in less than one hour of driving. WOT takes a lot of gas, but provided big grins.

[JeremyD]

My last track excursion - it was hot - 9.72 MPG Me after the day filling up

[hcoles]

Originally Posted by kach22i

How come the top part of the gas tank gets more miles per gallon than the last part? I was heading for 30 mpg, then had to switch to short trips and city driving over the weekend which killed it.

Is it the Reserve part of the dial?
CIS fuel consumption, what is normal?

is it the picture... or is your oil pressure a bit on the low side?

[kach22i]

Originally Posted by hcoles

is it the picture... or is your oil pressure a bit on the low side?

I think the rough rule of thumb is 10 psi per 1,000 rpm, right?

I think it's bound to be a tad lower than that when driving for almost an hour, but I could be wrong.

Looks like 23 to 3,000 to me in the picture.

[slw911SC]

My 3.0 SC gets 27 to 28 mpg @ 2800 rpm @ between 60 and 65 mph on premium gas.

[hcoles]

the numbers are on some threads around here somewhere.. I have the updated restrictors and I get 1 bar at warm idle.. and then seems to be above 3 bar most all the time when driving... I can't remember to tell you the truth... you might see if others with your car have that oil pressure at that rpm. Could probably throw out a post....and see. I mentioned in case you didn't notice or it was a recent lower reading.

[richde]

Originally Posted by rick-l

I just find it hard to believe that a car that had an EPA rating of 14 and 24 gets 30 cruising at 90 MPH.
http://www.fueleconomy.gov/FEG/bymake/Porsche1988.shtml

In the Car and Driver article from '84 I'm looking at the EPA is 20 and 32. They "observed" 17mpg, although I have no idea whatsoever what they could have been doing to get such low mileage.

I get 20 with very mixed driving, and 21-22 at 100mph on the autobahn although I suspect it's in dire need of the valve adjustment I'm going to give it this weekend.

[crustychief]

I get about 28 MPG bone stock.

[gestalt1]

does twin plugging help mpg? i would think that if you are getting a more complete combustion that less total gas is needed.

[jasonlee]

I can get about 27 mpg in my 82 SC, with cat bypass, but its usually lower, cause I have a hard time keeping me foot of the go fast pedal

[Crude Rudy]

The drag force increases as a function of the velocity squared.

Drive 80 mph instead of 65 mph and there is a whole lot more drag to overcome and a lot less mpg's.

If someone would please tell Obama this, maybe in addition to inflating our tires properly, if we went back to the Jimmy Carter 55 mph speed limit we could cutback enough on foreign oil consumption we could sell the excess to China and fund US Government run health care and early retirement for all.

Heck, if we lowered the speed limit to 35 mph we could save enough oil to all be able to work 25 hrs per week and retire at 50 like they do in France.

[hcoles]

during the last 55mph law.. I hated it.. with my new BMW 2002... :-) and 40cent gas
now it doesn't seem like a bad idea... retire and go to the track for fun

[KarlCarrera]

Bone stock, now at 120,000mi. 17-20 in town, and the best has been 27 highway running between 65 and 90mph over a 200 mile trip. The 10% ethanol isn't helping matters any! Man, I think that's great!

Karl
88 Targa

[Milo2361]

my 80 sc - - lately i've been doing mostly city driving and im hitting around 18... on the trip down here i averaged 87mph and got 24.9 mpg.... i guess its not too bad .... but how come when i go 65 im only getting 22mpg???

[rick-l]

Originally Posted by ChkbookMechanic

I'm amazed you've kept a record of gas mileage for that long. I don't even worry about the gas mileage in my cars anymore. I figure the cost per fillup is worth it for the sanity I retain when I drive the cars like they are meant to be driven.

I keep track of every ounce of gas I put in it since I got it ten years ago. I also do it for my WRX that I bought new in 2003. It is not that hard to do since I pay at the pump and get a receipt. Every so often clean out the glove box and type them in a spreadsheet.

I thought it would be an indicator that something was wrong with the car if it started going south. Turns out the legislature and EPA (ozone level requirements) have much more effect on my MPG than how I drive or the parts I put in the car.

I have also noticed that the tank to tank MPG calculations vary +/- 5 MPG from what I think they should be due to when the shutoff on the vapor recovery pump works.

For richde in germany that is a lot of work to go from liters and kilometers to miles and gallons. I like the BMW commercial where they show a BMW going by a gas station in a small town in southern Germany and the price is $9 per gallon. Shouldn't it read like $1.45? And my 2003 WRX sedan 5MT has gone 108235 miles and used 4661.420 gallons of gas for an MPG of 23.219 MPG probably similar to your 2005.