What kind of fuel mileage does your 928 get?
09-02-2012, 06:08 PM
#1
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What kind of fuel mileage does your 928 get?
My 86.5 auto was getting 13-15 with a disconnected O2 sensor (I got the car like that), stock exhaust, and blown out cats.
Now after installation of the correct O2 sensor, and a new 2.5" exhaust system with X-pipe and newer honeycomb style cats, I got 20.9/gallon today at a steady 75 MPH on the freeway, with no a/c.
I thought that was pretty good, as all of the old road tests that I have read for the 928 reported 16-17 MPG.
Now after installation of the correct O2 sensor, and a new 2.5" exhaust system with X-pipe and newer honeycomb style cats, I got 20.9/gallon today at a steady 75 MPH on the freeway, with no a/c.
I thought that was pretty good, as all of the old road tests that I have read for the 928 reported 16-17 MPG.
09-02-2012, 06:43 PM
#3
Rennlist Member
My current fuel log since I started using it.
The HIGH points are long trips out of town for work. <600mi trips out of town are hard to see, because they flatten out in the chart..but.20-22 long trips, 14-15 non highway (3500' mountain climb to/from work everyday).
The BIG low point, was a Thunderhill track day...the other low points were dyno/sharktune days.
88 Auto, 2.54:1 LSD, EIS intake, 3" exhaust, sharktuned during the entirety of this log.
Only today..will the supercharger become part of the dataset.
The HIGH points are long trips out of town for work. <600mi trips out of town are hard to see, because they flatten out in the chart..but.20-22 long trips, 14-15 non highway (3500' mountain climb to/from work everyday).
The BIG low point, was a Thunderhill track day...the other low points were dyno/sharktune days.
88 Auto, 2.54:1 LSD, EIS intake, 3" exhaust, sharktuned during the entirety of this log.
Only today..will the supercharger become part of the dataset.
09-02-2012, 07:14 PM
#4
Instructor
My 16v gets around the window sticker avg....17. However, it can vary quite a bit. On my trip to Sharks in the Mountains, I got around 18-19 going there (up into the mountains) and 19-21 coming back. I was pretty happy with that, and that enjoying the mountain trails so to speak. I do have a new y-pipe and put 85 exhaust manifolds on it, so I am sure the better breathing helps.
A side note, I do not know why,,,,but it seems that whenever I use Shell Premium, I get a 1-2 mpg better mileage. Of course depending on where you are, it usually is more expensive. I get it when I can.
A side note, I do not know why,,,,but it seems that whenever I use Shell Premium, I get a 1-2 mpg better mileage. Of course depending on where you are, it usually is more expensive. I get it when I can.
09-02-2012, 07:19 PM
#5
Drifting
I get around 13 in town and 19 on the highway, but I am in California and that is a special low pollution blend of gas from my understanding, which yields lower MPG. On my trip delivering it home from Denver is 2006, I'm pretty sure I got 22 or better.
09-02-2012, 07:23 PM
#6
Drifting
I have never tracked my mileage.
But I have notice that when it was running rich for romping around town and going to work it was low and it really burned the fuel on a 5 hour trip to the city.
Then one day I decided to turn down the fuel gama for a trip to the city and saved about 1/3 of the fuel burned on the previous trip.
I feel that it burns what it takes to drive a super car with the level of performance that I want. its not a Kia
But I have notice that when it was running rich for romping around town and going to work it was low and it really burned the fuel on a 5 hour trip to the city.
Then one day I decided to turn down the fuel gama for a trip to the city and saved about 1/3 of the fuel burned on the previous trip.
I feel that it burns what it takes to drive a super car with the level of performance that I want. its not a Kia
09-02-2012, 07:57 PM
#7
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Pretty consistent range of 15-17, depending on highway speed. 15.5 is about average for me at 70. I try to stay closer to 60 though, since that nets me 17 (or slightly over with the right conditions).
Shifting from 225/50/16 to 225/60/16 on my rears gained me close to 1 mpg by my calculations though. Running at 70 with those on the rear dropped my engine speed by ~150 rpm which seems to have given me a near 1 mpg gain (to slightly over 16 mpg).
Additional noticeable gains occurred with new plugs and wires. I do get noticeably less in states with higher ethanol blending requirements.
Best recorded was 18.5 running at 55.
Obviously numbers are slightly approximate and are not exact due to variances in fueling, etc.
Shifting from 225/50/16 to 225/60/16 on my rears gained me close to 1 mpg by my calculations though. Running at 70 with those on the rear dropped my engine speed by ~150 rpm which seems to have given me a near 1 mpg gain (to slightly over 16 mpg).
Additional noticeable gains occurred with new plugs and wires. I do get noticeably less in states with higher ethanol blending requirements.
Best recorded was 18.5 running at 55.
Obviously numbers are slightly approximate and are not exact due to variances in fueling, etc.
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09-02-2012, 08:04 PM
#8
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If my odometer worked I might have some Idea 
But seems to use a bunch of fuel when I track it ! Now if that speedo had marks above 85 MPH I would have some idea how fast.
But seems to use a bunch of fuel when I track it ! Now if that speedo had marks above 85 MPH I would have some idea how fast.
09-02-2012, 08:35 PM
#9
Rennlist Member
my 87 got almost 24 on my 800 mile drive home..
it was raining and was so nervous due to this being my first 928 and reading about all the issues... i was a nervous wreck...
i haven't checked since then.........
it was raining and was so nervous due to this being my first 928 and reading about all the issues... i was a nervous wreck...
i haven't checked since then.........
09-02-2012, 09:14 PM
#11
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My '86 averaged 22 on the way back from PA when I got it. Don't know after that since the ODO quit on that trip. I'm guessing quite a bit lower as it spends alot of time as a two speed.
09-02-2012, 09:29 PM
#13
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Pretty consistent range of 15-17, depending on highway speed. 15.5 is about average for me at 70. I try to stay closer to 60 though, since that nets me 17 (or slightly over with the right conditions).
Shifting from 225/50/16 to 225/60/16 on my rears gained me close to 1 mpg by my calculations though. Running at 70 with those on the rear dropped my engine speed by ~150 rpm which seems to have given me a near 1 mpg gain (to slightly over 16 mpg).
Additional noticeable gains occurred with new plugs and wires. I do get noticeably less in states with higher ethanol blending requirements.
Best recorded was 18.5 running at 55.
Obviously numbers are slightly approximate and are not exact due to variances in fueling, etc.
Shifting from 225/50/16 to 225/60/16 on my rears gained me close to 1 mpg by my calculations though. Running at 70 with those on the rear dropped my engine speed by ~150 rpm which seems to have given me a near 1 mpg gain (to slightly over 16 mpg).
Additional noticeable gains occurred with new plugs and wires. I do get noticeably less in states with higher ethanol blending requirements.
Best recorded was 18.5 running at 55.
Obviously numbers are slightly approximate and are not exact due to variances in fueling, etc.
My current fuel log since I started using it.
The HIGH points are long trips out of town for work. <600mi trips out of town are hard to see, because they flatten out in the chart..but.20-22 long trips, 14-15 non highway (3500' mountain climb to/from work everyday).
The BIG low point, was a Thunderhill track day...the other low points were dyno/sharktune days.
88 Auto, 2.54:1 LSD, EIS intake, 3" exhaust, sharktuned during the entirety of this log.
Only today..will the supercharger become part of the dataset.
The HIGH points are long trips out of town for work. <600mi trips out of town are hard to see, because they flatten out in the chart..but.20-22 long trips, 14-15 non highway (3500' mountain climb to/from work everyday).
The BIG low point, was a Thunderhill track day...the other low points were dyno/sharktune days.
88 Auto, 2.54:1 LSD, EIS intake, 3" exhaust, sharktuned during the entirety of this log.
Only today..will the supercharger become part of the dataset.
