14mpg? what am I doing wrong (or right)?
 

ok...these posts about people getting over 20mpg. My last tank calculated out to just under 14mpg. The car runs fine, but is this low? I will admit that I typically don't shift until 4K minimum, and prefer to be up around 5K. I also end up cruising at over 3K...I rarely see 5th gear, and sometimes not even 4th.

For those getting good mileage, are you hanging around 2K most of the time? If so, how do you pull that off? My car doesn't seem happy unless she's above 3K. Just curious...

That is about what I get in my 82 around town. Freeway was ~23, IIRC.

We will wait and see if that changes once it is back together.

Tom

lol I guess my MPG are 0 :).. about gallons of kerosene for cleaning and 0 miles on the car since I've bought it.

I can't even break 20mpg on all-freeway trips. Maybe I should get it out of 2nd gear...but it's so fun at 6K :)

I'm with you on the SC mileage, simillar if not hgher shift points. About 13-14 around town, 20 mpg down the freeway if i keep it around 2900 rpms.

The Carrera smokes the SC when it comes to mileage 20+ mpg is a breeze.

That does seem sort of low. I think I get around 12mpg on the track.
-Chris
'86 Carrera

I think an accurate method would be 5th gear at about 70-75mph

I have the C2 cams in my ‘81SC, and operate it much as you describe, hanging out for 4k and downshifting if when I hit 3k. I’m in the 19 – 20 mpg range. I commute in and out of Houston daily, about 10 miles worth of slow traffic – about 30 miles of 80 – 90 mph.

I did have my sensor plate adjusted a little high, and my mpg was down in the 15 range. I think what happens when the plate up, is that unaccounted air enters the throttle body causing the mixture to be rich to compensate. Since I adjusted the sensor plate down, the car is running better then ever, and the mpg are back up. Before the cam upgrade I was in the 21-23 mpg. I’m still adjusting.

I’m pretty sure your engine can be more efficient with some tweaking. Look at your sensor plate.

You Cali guys haven't figured it out yet? Gasahol delivers much poorer mileage than gasoline....who knows how much alcohol is in the "gas" you are forced to buy?

Yup - those big signs on the pump "NO MTBE!" means they're putting in alcohol.

Todd, you're not driving around with the e-brake on are you ;)

My '79 car, I don't know exactly what it does, but it sure does do more than 14. In fact compaired to other cars I've owned it's quite good. Also it doesn't seem to make terribly much difference keeping the revs up. I used to drive it in the 2-4,000 range, with a burst up to 5,000, until I was advised otherwise. Now I'm a 4-6,5000 man. And the fuel ecomnomy didn't seem to change.

It's interesting what GT911 said about the sensor plate.

OMG We have a howling gale blowing here in Wellington and I just watched a plane coming to the nearby airport. It looked like a duck on the opening day of the shooting season and it almost clipped a wing tip on the tarmac :eek:

I never thought of that. I was kind of proud about getting only 16 to 17 in the new RS America. Now it occurs to me that the bad gas mileage has more to do with the Gasohol and less to do with my heavy foot. Why did they put 5th gear in these things again? :D

Any ideas what 16 to 17 mpg on gasohol translates into for regular ethyl? Maybe 18 to 19?

Re: 14mpg? what am I doing wrong (or right)?
 

You're not driving hard enough! You should be getting half that!

Seriously: I thought hanging around 2K is a no-no anyway. 14 to 15 is about right for these cars. I think 20mpg is what happens when one does hang around 2,000 RPM -- in all gears.

But think of what that does to your engine in the long run.

2,000 RPM = 20mpg isn't a real good compromise for a motor that should be shifted at 4,500 to 5,000 rpm.

ok, so with the high alcohol content I start drinking the gas...that should increase something.

no info on a good question..

but, my humble 911 was getting fuel in many states a short time ago.. and although Calif gas may not be a prize, it's not that bad/Chevron.. and I did drive my brother's stock '88 911 around for plenty miles..

the bobby prize, IMO, is Indianapolis, Indiana.. No other place in the country made my car feel like it needed spark plugs on a flat drive.. forget about engine torque for road position/it sucked.. maybe the station owners piss in it/don't know

the best package in the US, IMO, is the SE US/generally speaking

Recently, in the local Ford dealer parking lot, while waiting for my wife's "chick truck" to get serviced, I noticed that some of the new Ford Rangers are stickered as "multi fuel"...meaning they can run on alcohol or gas. They run mileage figures for both on the sticker...quite an eye opener. But hey, you now have "NO MTBE"...and if they aren't telling you how much alcohol is in the "gas"...or as Cali calls it, "reformulated fuel", you are buying? Hell, 14 mpg in an SC could be great mileage!

Don't ***** guys, after the throttle body and sensor plate mods I got 14 to 17 on the highway and I don't even want to look at the mpg for the city.

But it is fast.

What and where's the sensor plate?
 

And can anyone explain what it does? How's it adjusted?

Thanks.

Hey Todd,
Forgive me for the basic question, but have you checked the timing and CO (mixture) levels? In addition, if you're cruising around town at 4000 rpm, that would explain the decreased mileage. Are these the same revs on the open highway?

Sherwood Lee
http://members.rennlist.org/911pcars

Good point, Sherwood. Like the new car stickers say: "your mileage may vary"...