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No, no. You must calculate your gas mileage mathematically. If you're recording your MFD figures into greenhybrid's database, you are NOT using the most accurate figures possible.

Even with the variable bladder of the Prius, you will still be very accurate when calculating over the course of multiple fill-ups.

The MFD figure is only an ESTIMATION. Whereas the mathematically-calculated number is HOW FAR you drove on HOW MUCH gas.

That's gas mileage, folks. Maybe not accurate for one single tank, but as I said, from tank-to-tank-to-tank, it equalizes out, and is in fact, extremely accurate.

Mr. Mage! Congratulations, my friend! And it's good to see that you made it through the storm too!
 

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hdrygas said:
...The place I get my gas has not had the pump inspected in 3 and 3/4 years!! You are assuming that what you pay for is what you get, that may not be true. A regional TV report on gas pumps reviled more than half to be off and most in the favor of the station. Washington State has 3 inspectors according to to the Tacoma paper. Can you trust your pump. Some states are good some are bad. What are you going to do!!?
Jamarimut's response seemed to be an attempt to deflate Mr. Mage's enthusiasm at getting great gas mileage by taking a shot at the accuracy of the variable bladder gas tank. The gas tank doesn't shrink when the temperature is above 40f, and it's Florida in August. Given this information, I think Mr. Mage's calculations are more accurate than the MFD.

Note also that Jamarimut did not mention inaccurate pumps at the gas stations as part of his reasoning.

And of course, I cannot read minds, therefore I responded to his claim that the MFD is more accurate than mathematical calculation.

I live in Mr. Mage's town. Our state and town have good enforcement with regards to weights and measures. Owners/operators of inaccurate pumps could be prosecuted as fraudulent in the state of Florida.

If you have a fraud problem in your state, then there's little that can be done to insure accurate mileage calculations. In fact, you have a more serious problem on your hands, and I would urge you to complain to the appropriate authorities. Or sue. Surely you can find a lawyer to take the case as a class action in the interest of the public in your state. There may be a shortage of inspectors, but the last I heard, there was no shortage of lawyers. :? Remember too, if this type of fraud is allowed to continue, then there's no telling what other types of fraud are happening.

If it's a losing battle no matter what you do, then maybe other things are more important to the people in your state. After all, we as a society usually get what we want.

In any case, I stand by my original statement. The MFD is only an estimate, using the amount and and duration of fuel injector flow. Personally, I have wild fluctuations between MFD and calculated mileage whenever I burn less than a half-tank. The differences are slimmer when I burn nearly the whole tank.
 

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...but from tank to tank to tank to tank, it doesn't matter so much whether you fill up at the same pump.

Because over time, you will still be recording how far you drove on how much gas. And somebody mentioned 20 tankfulls. I don't know how the magic number became 20...that doesn't make sense. I think even three tankfulls, particularly if you're filling up more than half the tank each time, would be pretty accurate. And nobody stops driving their car after three tankfulls. We keep driving. The overall margin of error will get less with each new tankful.


And when all is said and done, some of us just want to measure our mileage. So leave us be, let us measure our mileage, and let us get excited and enthusiastic when we have a good tank! After all, somebody else's good measurements aren't hurting you, are they? :?
 

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SLowen said:
BIF said:
And when all is said and done, some of us just want to measure our mileage. So leave us be, let us measure our mileage, and let us get excited and enthusiastic when we have a good tank! After all, somebody else's good measurements aren't hurting you, are they?" :?
Whats up with this statement?
I had inferred, whether right or wrong, that a couple of posters had jumped on Mr. Mage for his excitement and enthusiasm for having a good tank, and I was simply responding to a couple of posts that I had interpreted as "why bother measuring" or "yeah, big deal, it doesn't really count anyway because you can't measure gallons, miles, etcetera accurately".

Sheesh, with a responses like that, where's the incentive to share good experiences? It's like when something really nice happens in your life, and you go to tell a friend all about it, and they respond with something like "Why bother living and being happy, we're all just gonna die sooner or later anyway...."

Maybe I overreacted, but I perceived it to be a real downer, and naturally, I came to Mr. Mage's defense.

Are you saying that we should not post information about gas mileage? Are you saying that if you get a sudden drop in mileage because of low tire pressure or some mechnaical problem that it should be ignored as long as the lifetime mileage is OK? That could be a long time if you have a lot of miles on the car.
No, of course not. I don't know how you inferred that from my post, which essentially said, "let us calculate if we wish."

This post was started as a "Wow, I got great mileage!", and it turned into a discussion about gas pump inaccuracies. How did that happen?

No one is trying to get you to do anything, but if people are presenting false mileage info based on bad math, then YES it hurts the Prius community’s credibility.
I know that nobody is trying to get me to do anything, but I will say that in my experience, there are a lot of people who will try to play down any success that somebody may have. "MFD is more accurate." "Foul! Variable bladder! Yellow card for you!" "You can't get good gas measurement at most gas stations", blah, blah, blah.

Once again, my response was "Some of us just want to calculate and take the time and be excited about our gas mileage. It's not hurting you, so just leave us be rather than try to take us down or deflate our excitement at every turn." If I have misinterpreted somebody else's intent here, then I sincerely apologize. But I can only go by what I read. And what I read was "hey, I got a great tank!" followed by a bunch of seemingly pessimistic "yeah but" "yeah but" "yeah but" by other people who would normally have been supportive.

If innacurate gas pumps are a problem, then let's discuss it. In fact, it probably would be very very interesting. But I humbly suggest that maybe we start a thread about that problem. Potential eye-catching subject lines might include "Proven innacurate pumps at Citgo station in Buglump, Idaho!", or "Have you ever gotten defrauded by a gas pump?"

Have a great day!
 

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Hi, Henry!

Thanks for the rephrasing. I think we're on the same wavelength.

I wonder if maybe it would pay to pump gas into a container of known volume, such as a 5-gallon can.

It would be interesting to see how "off" the pump is, not just for one gallon at a time, but for something of greater quantity, like a 5-gallon jug.

...just a thought.

Have a super day!
 
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