10 MPG!!!! What kind of mileage do you get?
 

granted I've got a 7:31 r/p so the car is geared short and I hammer on the throttle all the time but this 3.0 w/ webers is really thirsty.

I have 86' 930 and gets 12-14mpg mixed driving. For 3.0 seems excessive

I get about 10 MPG in my 72 with a 7:31 3.2L and 46 PMOs

I was getting about 15mpg in my 3.0l SC, but since I installed an oxygen sensor, I'm now getting around 18mpg. It's really made a difference from about 175 miles per tank to about 250. I was pretty impressed...

I'm getting just under 17, mostly intown driving. No mods to engine.

Pumper carbs are bad around town for gas mileage. My last 2.0L 914 had the IDF's and I would get 12-14mpg in town and 30mpg on the highway. My Dad's 912 has the same mileage numbers. Every time you hit the gas, you get that extra squirt from the accelerator pumps.

Unless something is mechanically wrong, your fuel economy is dramatically (perhaps almost totally) a result of your driving. That can include how heavy your right foot is, the kind of driving situations, and the overall speeds.

During the oil embargo in ’74, I took a 2.0T, raised the CR, made smaller yet Weber venturi, and jets within an inch of its life. I got 42 MPG regularly. Of course it wasn’t the 911 we know and love in terms of drivability and performance.

Today I would raise the CR even more, have twin plugs, smaller valves, and Nikasil cylinders. I would also apply most of the race engine "tricks" because they typically reduce losses.

EFI with feedback will let you run even closer to the limit. At the flick of a switch you can go from “economy” to “performance.”

Best,
Grady

Well Grady 42 MPG is surprising, maybe I'll have you build my next economy car. a 42 MPG 911 sounds better than the diesel jetta I've been thinking about.

seriously, I know I am suffering from too much right foot although this car is running pretty rich right now. I guess the Mod S. cams, ported heads and 36 mm venturis help suck the fuel down too.

When I had the 2.7 RS pistons, solex cams, webers w/ 34 mm venturi and small port heads I actually got pretty respectable gas mileage and an engine that was a whole lot of fun to drive.

Around town, short drives, seldom up to temp, I get about 12 MPG in my 1979SC. On the open road, driving fast, it's more like 26. As Grady says, it's all about how you drive.

15 mpg in stop-n-go traffic around town -- low to mid 20's on hiway.
Chipped 3.2, 1987 Targa.

'71 911T with PMO's get 17mpg on the freeway
'91 C2 will get high 20's mpg on the freeway

73.5 2.4 T with 40 Webers:

Track: 9-12 mpg
Country road, spirited driving 15-18 mpg
Interstate, cruising 20-22 mpg

"It's really made a difference from about 175 miles per tank to about 250. I was pretty impressed..."
yikes...


i drove 375 miles on a tank last week... granted it was 20gal and the trip was 6000'ft downhill:D
this was with 79 3.L

all the joy i receved "saving money" wend out the window when i checked the price of gas when i did stop...

16.7 MPG with K&N filter (THANK YOU VERY MUCH)
14.1 MPG with Paper Filter

HP increase, none.

I am getting an average of 350-375 miles on a tankful, filling up when the light illuminates. 3.5L twin-plug with plenty of power.

About half "city" driving and half highway cruising, not running to redline from stoplight to stoplight but not getting passed by mini-vans either. Steady 80-85 mph cruising on back roads or on the freeway.

The 3.5L actually has a slight increase in fuel efficiency over the original 3.2L with a few bolt-on mods if driven in a somewhat identical manner.

Some of you sure have thirsty cars.

Ralph

1988 3.2 hard driving around town get 19mpg

on the interstate at 85-90, 27mpg

two seperate trips a year apart were the same results 27mpg:D

About 9 MPG HWY, and in the city............LMAO Forget any kind of economy at all. :( Of course my foot might have a little to do with that but being good sucks with these cars.

77 930 with all the goodies!

'87 3.2 24mpg highway, 18 in town takin' it easy, 14-15 with my foot in it

The 36mm venturi is too large for street use. Try 32mm venturi's. Your mileage will improve, along with low end torque. You may need to resize your main jets as well. My 2.7 race car with solex cams, 9.5:1 pistons and headers, actually gained horsepower and mid range torque when I went from 36mm to 32mm venturi's. I was told by a experienced Porsche racing mechanic the 40mm webers do a much better metering job with 32mm venturi's. I believe him after I made the change. Let us know what you end up with. Good Luck.

In Maryland and the east to west coast roadtrip: 21-22 mpg
In Hawaii: 15 mpg