32.85 Mpg?!

[Vendetta]

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.

but at the same time.
-V

[89Vette]

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]

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.

The fill-ups were identical.

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]

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]

to ALL...

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]

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.

The fill-ups were identical.

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]

Downhill in both directions?

[JoFotoz]

Ya do know its St Pattys day....

...not April 1st


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


jo

[Vendetta]

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]

And there can now be world peace!

[blacksambo]

That's more like it.

[Vendetta]

But I did like very much the Escher-esque, downhill in both directions suggestion. If only...
-V

[89Vette]

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!

[atilla_the_fun]

I'm sorry, but getting free gas (being charged a lower rate) is as magical as the 32MPG figure!!!!!!!

[BeeVenom]

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!