gas mileage

Series I L27 (1992-1994 SE,SLE, SSE) & Series II L36 (1995-1999 SE, SSE, SLE) and common problems for the Series I and II L67 (all supercharged models 92-99) Including Olds 88's, Olds LSS's, Olds 98 91-96, Buick Lesabres and Park Avenue 91-96. Please use General Chat for non-mechanical issues, and Performance and Brainstorming for improvements.
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lackawanna1701
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gas mileage

Post by lackawanna1701 »

ok so ive gased up all the way with premium. I resetted the trip counter and its at 155 with "check gagues" light on. Is this good mileage on a 93 non-supercharged engine? I was gassing up with unleadeded and barely getting 100. Any insight would be helpful.
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Re: gas mileage

Post by gonzo4191 »

that seems quite low well wait, city or highway?
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Re: gas mileage

Post by harofreak00 »

You don't need to run premium in an N/A. Just a waste of money.

150 miles to a tank? Thats HORRIBLE. 8.3 MPG!

The gauges on 92-99 bonnies are silly. You should be able to get 100 miles out of the tank before it even gets past the "F". Then you should get another 200-250 miles until the gauge shows "half", and then you will probably get 100 miles out of the empty side of the tank.

You need to check your codes. Here is how to do it on a 93: http://www.extreme-check-engine-light-c ... ecoder.htm
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Re: gas mileage

Post by bonnevillain »

yeah, as haro mentioned premium will not get you better mileage. are you sure the chack gauges is not for something else?
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Re: gas mileage

Post by Hans »

You should be getting 400 miles out of the tank.

That is 23mpg = mixed city and highway. This is a good average if you are not flooring it.

500 miles in strictly highway driving, and 350 miles in strictly city driving.

Some members on here claim to get 31mpg/550 miles on a tank...I've gotten close, and this is with a supercharged car.
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Re: gas mileage

Post by freneticburn »

in my 98 SE with regular I had somewhere between 21-22 MPG mixed freeway and city the last time I checked which was about 2 weeks ago. What I do is fill my tank, reset the trip meter and once my check gauges light goes on, I'll go fill up, check my receipt or the pump for how many gallons I just pumped, take what your trip says (in my case it was 295 miles), and divide that by what you pumped (in my case it was a little bit over 14 gallons). That's the best way to do it without a fancy dashboard.

The gauges cannot be taken for exact. My gauge will sit at full or slightly past for like 70 miles. And I'm pretty sure it's not my imagination but it seems the latter half of the tank, according to the gauge, goes quicker than the first half.



I should also mention I had some crappy gas mileage until I recently changed my front O2 sensor. I also checked my coil packs with some advise from these forums and found out 2 of the 3 were going bad. So I also replaced all 3 not that long ago.
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Re: gas mileage

Post by Adeianos »

In my 98, I was getting 23, dropped to 18 when I needed to replace a couple of the injectors (never got around to it before I sold it).
In my 92, I was getting 21 while delivering pizza.
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Re: gas mileage

Post by 93RedSled-SSE »

lackawanna1701 wrote:ok so ive gased up all the way with premium. I resetted the trip counter and its at 155 with "check gagues" light on. Is this good mileage on a 93 non-supercharged engine? I was gassing up with unleadeded and barely getting 100. Any insight would be helpful.
harofreak00 wrote:You don't need to run premium in an N/A. Just a waste of money.

150 miles to a tank? Thats HORRIBLE. 8.3 MPG!

The gauges on 92-99 bonnies are silly. You should be able to get 100 miles out of the tank before it even gets past the "F". Then you should get another 200-250 miles until the gauge shows "half", and then you will probably get 100 miles out of the empty side of the tank.

You need to check your codes. Here is how to do it on a 93: http://www.extreme-check-engine-light-c ... ecoder.htm
Yes, that IS lousy. My 93 goes for about 19 MPG city and high 27+ highway. You may be running in "limp home" mode due to a problem in you engine management. It will drink gas bad in that mode.

Q: Is the "Service Engine Soon" (SES) or "Check Engine" Light (CEL) coming on?

If so, yours is easy to check without any special tools. Here is all it takes:

You should have this computer port below the steering column.
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Do NOT disconnect the battery. That would be bad, because it will erase the codes you have stored.
Here is the procedure in brief. So take a pen and paper to write them down.
1. Basically you are going to short A & B together with the bent bare metal paper clip.
2. Then, turn the key on, but don't start.
3. If you watch the Service Engine light, it will start flashing.
4. First it will do "1" flash, followed by "2" flashes, which is a "12" and says the diag. is working.
5. After flashing "12" 3 times or so, Start watching and counting.
6. The first digit will flash (count) then the 2nd digit.
It will do this 3 times before going to the next code.
7. When it has displayed all the codes this way, it repeats, coming of with the "12" again.
8. You can shut it down and remove the clip now.
9. To translate the codes you get, see this one in Tech Info http://www.pontiacbonnevilleclub.com/fo ... =51&t=1626

NOTE: It will display any codes stored since they were last cleared. So you may see some old ones too. Write them all down, etc. That way, you can later disconnect the battery to clear them and start over, with your test drives, or whatever, and see what codes are gone and which ones are showing up now.

Let us know what you find.
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Re: gas mileage

Post by Bob Dillon »

freneticburn wrote: My gauge will sit at full or slightly past for like 70 miles. And I'm pretty sure it's not my imagination but it seems the latter half of the tank, according to the gauge, goes quicker than the first half.
It's not your imagination, it's the shape of the tank. It's "L" shaped with the vertical stroke of the "L" pretty thick and the horizontal stroke pretty slim.

I noted how weird looking mine was when I changed the fuel pump.
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Re: gas mileage

Post by 92BonneSE »

I get at least 200 miles to a half tank in 100% city, so yes, that is pretty bad.
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