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Vendetta
03/17/2012, 12:34 PM
Filled up this morning, topped it off. To the brim.

Drove 105.1 miles (adjusted 10.48% from 95.2 on the odometer because if tire size) from the gas station, to the salvage yard, and back to the gas station, same pump.

Filled up, topped it off. To the brim. 3.2 gallons.

Unless my math is way off, then I just got 32.85 MPG for this stretch. How is that even possible???

The trip was I'd say about 92% highway miles and the rest rural "city" traffic. Engine light is still on with the following codes:
P1171 - Fuel System Lean During Acceleration
P0157 - O2 Circuit Low Voltage (Bank 2 Sensor 2)
P0137 - O2 Circuit Low Voltage (Bank 1 Sensor 2)
(I'll research these later)

Power mode OFF.

:_confused but :clap: at the same time.
-V

89Vette
03/17/2012, 02:32 PM
The pump is malfunctioning and shutting itself off too early (since your prior fill).

Assuming your gauge is like mine, I drive about 50 miles before it drops down from the full marke. Basically, that means you've got a 2.5 gallon buffer where the tank can look full -but not BE full.

I also suspect you might have gotten it more full than usual on your prior fill-up.

This is why you can't accurately measure fuel usuage with less than one tank of fuel. Ideally you want at least two/three tanks before drawing any conclusion.

Would have been nice though!!!

(BTW...Another possibility is your O2 sensor is going bad and you're actually running way too lean!!! And, that would be very bad.)

Vendetta
03/17/2012, 02:47 PM
It's not the pump. It was the same pump I filled it with earlier in the day. (And countless times prior.) Plus, after the gazillion or so fill-ups I've performed on this thing in the decade I've owned it, I know then deal when it comes to topping it off. :yesgray:

The fill-ups were identical (http://www.youtube.com/watch?v=i2nuPVTU4Z4).

No cruise control, consistent throttle maintaining ~65 actual MPH @ 2300 RPM.

I don't believe I'm running lean - as in that lean, anyway. I imagine I'd be experiencing all sorts of problems if I were?

-V

Triathlete
03/17/2012, 03:04 PM
My last tank I got over 350 miles before the light came on...probably could have squeezed another 10-15good miles out of it.

Ldub
03/17/2012, 03:40 PM
:fyi: to ALL...:_wrench:

I've heard that topping off, or filling to the brim, can damage the charcoal filter cannister in the emissions system.

"The EPA also warns consumers that topping off can affect the performance of your vehicle. This is because your car or truck was designed to have additional room in the gas tank. The vehicles are configured in this way to allow room for the gas to expand. When you top off, you are eliminating that room for gas expansion; instead, it will evaporate into other areas of the vehicle, like the vapor collection system. This will cause the system to work improperly, leading to poor performance and higher gas emissions."

89Vette
03/17/2012, 05:40 PM
It's not the pump. It was the same pump I filled it with earlier in the day. (And countless times prior.) Plus, after the gazillion or so fill-ups I've performed on this thing in the decade I've owned it, I know then deal when it comes to topping it off. :yesgray:

The fill-ups were identical (http://www.youtube.com/watch?v=i2nuPVTU4Z4).

No cruise control, consistent throttle maintaining ~65 actual MPH @ 2300 RPM.

I don't believe I'm running lean - as in that lean, anyway. I imagine I'd be experiencing all sorts of problems if I were?

-V

Well...there's no way you got 33mpg, so what's your theory? Recheck your receipt, maybe? 50mpg tailwind both ways? Microburst that lasted 3hrs? LOL

rsteinmetz70112
03/17/2012, 07:04 PM
Downhill in both directions?

JoFotoz
03/17/2012, 07:27 PM
Ya do know its St Pattys day....

...not April 1st :rolleyes:


Perhaps ya had a touch of the Irish in ya today!


jo

Vendetta
03/17/2012, 08:51 PM
On a hunch (thanks, Vette), I checked the receipt and even went back to the store to validate the pump number. Turns out I was charged for someone else's lesser amount.

Did a recheck against the actuals and reality is that today's ~100-mile junket saw me running just a tick above 17mpg.

I actually prefer having the real data over some ridiculous, mystery MPG figure.

Now I can sleep.
-V

Triathlete
03/17/2012, 09:30 PM
And there can now be world peace! :D

blacksambo
03/17/2012, 09:35 PM
That's more like it.

Vendetta
03/17/2012, 09:36 PM
But I did like very much the Escher-esque, downhill in both directions suggestion. If only...
-V

89Vette
03/18/2012, 09:24 AM
But I did like very much the Escher-esque, downhill in both directions suggestion. If only...
-V

Here, let me help....

17MPG times both ways (x 2) means 17x2=34MPG.

See! You are getting awesome mileage!

:snooz:

atilla_the_fun
03/18/2012, 09:36 AM
I'm sorry, but getting free gas (being charged a lower rate) is as magical as the 32MPG figure!!!!!!!

BeeVenom
03/18/2012, 02:25 PM
I think we all have that 'infamous' 4.30 axle ratio....99 thru 01. So, with that said, and unless you changed yours out, I think we all know the possibilities for 30+ mpg! :p

evillecutter
11/13/2012, 06:25 AM
i was at half a tank yesterday - we have a 22.5 gallon tank - but to get it all the way full only took a little over 6 gallons... when i did the math i am getting about 18 mpg in city since changing the exhaust to free flowing - got about 14 before - could be coincidence but in happy either way - not sure what to do about my gas guage though

cheetah2390
11/13/2012, 08:05 AM
i was at half a tank yesterday - we have a 22.5 gallon tank - but to get it all the way full only took a little over 6 gallons... when i did the math i am getting about 18 mpg in city since changing the exhaust to free flowing - got about 14 before - could be coincidence but in happy either way - not sure what to do about my gas guage though

Any pics????

evillecutter
11/13/2012, 01:07 PM
sorry when i said exhaust i meant muffler (only $75 so if it really does help my mpg it will pay for itself in a few tanks) - im working on getting pics uploaded of the new muffler and the old oem one that i cut apart and should have them on here soon

ZeroSix
11/13/2012, 03:07 PM
Since we are on the gas milage bug:

http://www.ebay.com/itm/140755700569?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

does having the intake make a difference for the VX? i was just gonna get the tube and swap a better filter....

35... that would have been a dream....

pbkid
11/13/2012, 04:27 PM
Not a noticable amount zerosix. You will feel more pickup but not significant improvement in mileage

89Vette
11/13/2012, 05:09 PM
sorry when i said exhaust i meant muffler (only $75 so if it really does help my mpg it will pay for itself in a few tanks) - im working on getting pics uploaded of the new muffler and the old oem one that i cut apart and should have them on here soon

Is that with a generic "turbo" muffler? What's the approx body size?

Your MPG improvement is awesome...and I hope the pics will lead us to the realization that the OEM mufflers might be hurting us more than we think (if/when that valve sticks).

Looking forward to pics!

89V

Mile High VX
11/13/2012, 05:26 PM
Not a noticable amount zerosix. You will feel more pickup but not significant improvement in mileage

I added a cold air intake like this to my V6 Accord Coupe and the mileage went down...can't imagine why but every time I drove it I found my right foot very heavy and my ears enjoying that wonderful sound...:bwgy::smilewink:bgwo::bgwb:

pbkid
11/14/2012, 06:05 AM
I added a cold air intake like this to my V6 Accord Coupe and the mileage went down...can't imagine why but every time I drove it I found my right foot very heavy and my ears enjoying that wonderful sound...:bwgy::smilewink:bgwo::bgwb:

Huh... Funny, i had the same problem with the cold air intake on my VX

evillecutter
11/14/2012, 06:40 AM
new muffler - says "made in the usa" just like me :)

http://www.vehicross.info/gallery/data/500/medium/Picture_0111.jpg (http://www.vehicross.info/gallery/showphoto.php/photo/23049)
http://www.vehicross.info/gallery/data/500/medium/Picture_0122.jpg (http://www.vehicross.info/gallery/showphoto.php/photo/23050)

link to thread with pics of inside of oem muffler:
http://www.vehicross.info/forums/showpost.php?p=269783&postcount=26

yellowgizmo99
11/14/2012, 07:56 AM
evil this is the thread
http://www.vehicross.info/forums/showpost.php?p=269783&postcount=26

evillecutter
11/14/2012, 08:34 AM
evil this is the thread
http://www.vehicross.info/forums/showpost.php?p=269783&postcount=26

thanks i think i got er fixed now :o

ThisGuyIndy
11/14/2012, 11:31 AM
I had a dream that I was a muffler...woke up exhausted :)

evillecutter
11/14/2012, 12:33 PM
I had a dream that I was a muffler...woke up exhausted :)

:dan_ban:

Leon R
11/14/2012, 02:37 PM
This is called “experimental error”, the smaller your sample, the greater the possibility that your experiment will be flawed! Next time, drive it longer ;).

If, for some reason, you were FORCED to fill up after 100 miles, you would have to perform 10 such experiments and then average them out.

Edit: Just realized that this thread is quite old... :o

89Vette
11/14/2012, 10:39 PM
Edit: Just realized that this thread is quite old... :o

Yep... Now it's getting exhausted! Maybe it's time to muffle it?

:p