Ive had this happen once before. I also thought I had hit the jackpot! Anyway to counter this I always go to the same gas station and use the same pump. Has worked ever since the Chevron screwed my road trip mpg.
Here is why calculated MPG is unreliable.
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If you are really serious about measuring your fuel economy, always print the receipt at the pump and note down the actual miles (odometer, NOT Trip meter) reading. This requires that you keep information for *all* of your fills. Enter that information in the Excel file and then dissect the data. You can then look at the mileage of this tank, last three tanks, lifetime average etc. You can see the trends. You can see how season affects your mileage etc.
Anything less, and you are not serious about fuel economy.
Personally, I did that for a while but now I don't bother. I do the mental calculation for every tank and unless there is a significant variation from the usual trend, I no longer worry about. I *know* that the biggest contributor to the mileage is the nut behind the wheel and I have proven it to myself beyond any shadow of doubt
- Vikas
Anything less, and you are not serious about fuel economy.
Personally, I did that for a while but now I don't bother. I do the mental calculation for every tank and unless there is a significant variation from the usual trend, I no longer worry about. I *know* that the biggest contributor to the mileage is the nut behind the wheel and I have proven it to myself beyond any shadow of doubt
- Vikas
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This is the reason why I add "another click" after the first auto-click shuts off. Cause I've had some "wonky pumps" shut off on me after only putting in 2-3 gallons......so I had to keep pressing the trigger on the gas pump and was going "[censored]?" I knew the car was low on fuel, but the gas pump kept shutting off like it was "full" but the tank was 1/2 full.....stopped going to that Chevron station and no more problems
I run every tank about 20 miles past the fuel light coming on, and after almost 200K miles on the two Infiniti's, I know within .5 gallons, how much it is going to take. It is very consistent and I also know what kind of mileage I get depending on my driving. I know when my calculations don't add up - whether it is due to a headwind or an optimistic pump. Also they will both fill up to the point that after it clicks off, one more pull and gas will spill out the fill-hole.
G35 95% of my non-track or mountain road tanks fit into the following
Highway miles 21-22mpg.
Highway miles w/ trailer 16-18mpg.
City miles ~18-19, but harder to predict.
FX Highway 16-17
w/ trailer 13-14
City 10-14
The consistency is amazing. I guess the fact that most of my trips are over 1K miles helps.
G35 95% of my non-track or mountain road tanks fit into the following
Highway miles 21-22mpg.
Highway miles w/ trailer 16-18mpg.
City miles ~18-19, but harder to predict.
FX Highway 16-17
w/ trailer 13-14
City 10-14
The consistency is amazing. I guess the fact that most of my trips are over 1K miles helps.
Originally Posted By: CBR.worm
Also they will both fill up to the point that after it clicks off, one more pull and gas will spill out the fill-hole.
Is "spill" a euphemism for "pour out all over the place" like it is for my G? I thought the Audi was bad for gushing fuel during fillups.
Also they will both fill up to the point that after it clicks off, one more pull and gas will spill out the fill-hole.
Is "spill" a euphemism for "pour out all over the place" like it is for my G?
I thought the Audi was bad for gushing fuel during fillups.Even using the same pump has faults. example- filled my diesel pickup yesterday at a Murphy, the pump shut off at $100.00.
Needed more so card swiped again...noticed this time the output flow of the pump was considerably less than the first time...don't know why. So much for the same pump theory being consistant as the exact same pump literally less than a minute later had a vastly different flow rate meaning the auto shut off would be in a much different place in my truck as it backs up the neck some with a higher rate.
Now in my case if I'm really patient I can fill up to the brim of the neck since there are no charcoal canisters to worry about, but it is a slow process to dribble in that last couple of gallons. This is complicated because many diesel pumps, even the "auto diesel" ones seem to flow much faster than similar gasoline pumps. For some reason the littlest one can squeeze the handle results in more flow than wanted trying to "top off".
I never top off on gasoline vehicles because this can cause problems with the emission systems in some vehicles if one does so.
Needed more so card swiped again...noticed this time the output flow of the pump was considerably less than the first time...don't know why. So much for the same pump theory being consistant as the exact same pump literally less than a minute later had a vastly different flow rate meaning the auto shut off would be in a much different place in my truck as it backs up the neck some with a higher rate.
Now in my case if I'm really patient I can fill up to the brim of the neck since there are no charcoal canisters to worry about, but it is a slow process to dribble in that last couple of gallons. This is complicated because many diesel pumps, even the "auto diesel" ones seem to flow much faster than similar gasoline pumps. For some reason the littlest one can squeeze the handle results in more flow than wanted trying to "top off".
I never top off on gasoline vehicles because this can cause problems with the emission systems in some vehicles if one does so.
I go fastest notch to shutoff.. a slow shutoff.
and track my mileage at fuelly. its pretty consistant.
The in car meter is very accurate... its always 1mpg high (oops)
fuelly link . (note the dips are from trailer towing)
Usually I get a nice 27-28mpg tank going then boom 100miles of towing an airbrake later its back down to low 24's
and track my mileage at fuelly. its pretty consistant.
The in car meter is very accurate... its always 1mpg high (oops)
fuelly link . (note the dips are from trailer towing)
Usually I get a nice 27-28mpg tank going then boom 100miles of towing an airbrake later its back down to low 24's
I usually use the same fuel pump and let the fuel gauge go down to about about 1/3 full. Fill to the first click and over 3 weeks its averages within 0.2 of mpg providing you are measuring the vehicle using similar trips and conditions eg city driving, country driving or mix or both.
Even with the OEM mpg which is done under controlled lab conditions this is usually quoted within 0.2mpg increments.
If your vehicle averages for example 25mpg with a 3% error this translates to 0.75mpg discrepancy. So what are we losing sleep over stuff that is well within meaningful tolerances?
Even with the OEM mpg which is done under controlled lab conditions this is usually quoted within 0.2mpg increments.
If your vehicle averages for example 25mpg with a 3% error this translates to 0.75mpg discrepancy. So what are we losing sleep over stuff that is well within meaningful tolerances?
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Originally Posted By: Vikas
If you are really serious about measuring your fuel economy, always print the receipt at the pump and note down the actual miles (odometer, NOT Trip meter) reading. This requires that you keep information for *all* of your fills. Enter that information in the Excel file and then dissect the data. You can then look at the mileage of this tank, last three tanks, lifetime average etc. You can see the trends. You can see how season affects your mileage etc.
Anything less, and you are not serious about fuel economy.
Personally, I did that for a while but now I don't bother. I do the mental calculation for every tank and unless there is a significant variation from the usual trend, I no longer worry about. I *know* that the biggest contributor to the mileage is the nut behind the wheel and I have proven it to myself beyond any shadow of doubt
- Vikas
I do this on 3 vehicles. Im a little nutty
If you are really serious about measuring your fuel economy, always print the receipt at the pump and note down the actual miles (odometer, NOT Trip meter) reading. This requires that you keep information for *all* of your fills. Enter that information in the Excel file and then dissect the data. You can then look at the mileage of this tank, last three tanks, lifetime average etc. You can see the trends. You can see how season affects your mileage etc.
Anything less, and you are not serious about fuel economy.
Personally, I did that for a while but now I don't bother. I do the mental calculation for every tank and unless there is a significant variation from the usual trend, I no longer worry about. I *know* that the biggest contributor to the mileage is the nut behind the wheel and I have proven it to myself beyond any shadow of doubt
- Vikas
I do this on 3 vehicles. Im a little nutty
Originally Posted By: Dominic
Originally Posted By: Vikas
If you are really serious about measuring your fuel economy, always print the receipt at the pump and note down the actual miles (odometer, NOT Trip meter) reading. This requires that you keep information for *all* of your fills. Enter that information in the Excel file and then dissect the data. You can then look at the mileage of this tank, last three tanks, lifetime average etc. You can see the trends. You can see how season affects your mileage etc.
Anything less, and you are not serious about fuel economy.
Personally, I did that for a while but now I don't bother. I do the mental calculation for every tank and unless there is a significant variation from the usual trend, I no longer worry about. I *know* that the biggest contributor to the mileage is the nut behind the wheel and I have proven it to myself beyond any shadow of doubt
- Vikas
I do this on 3 vehicles. Im a little nutty
I also do it. The car MPG readout is surprisingly accurate. Almost good enough that one could think the car tells the pump "Don't give me more than 14.64 gallons today or my owner will catch on to us!"
Originally Posted By: Vikas
If you are really serious about measuring your fuel economy, always print the receipt at the pump and note down the actual miles (odometer, NOT Trip meter) reading. This requires that you keep information for *all* of your fills. Enter that information in the Excel file and then dissect the data. You can then look at the mileage of this tank, last three tanks, lifetime average etc. You can see the trends. You can see how season affects your mileage etc.
Anything less, and you are not serious about fuel economy.
Personally, I did that for a while but now I don't bother. I do the mental calculation for every tank and unless there is a significant variation from the usual trend, I no longer worry about. I *know* that the biggest contributor to the mileage is the nut behind the wheel and I have proven it to myself beyond any shadow of doubt
- Vikas
I do this on 3 vehicles. Im a little nutty
I also do it. The car MPG readout is surprisingly accurate. Almost good enough that one could think the car tells the pump "Don't give me more than 14.64 gallons today or my owner will catch on to us!"
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