MPG & UFollow

I'm going to have to see more math I don't understand before I can take any of this seriously.

The point is that L/100km is the most effective way of measuring full efficiency.

As interpreted literally, you're establishing here for him that the there is more to this difference than merely getting to multiply by gpm to calculate the cost of a trip than divide by mpg.


Basically you keep telling Gbaji there's this special difference beyond merely being able to multiply distance by gpm to get a trip's cost instead of dividing by mpg. He keeps being confused. You keep telling him he's wrong in how he understands it. He's not.

This misunderstanding has been almost entirely what Gbaji and you have been discussing.

This misunderstanding

There is no misunderstanding. Gbaji has no interest in what's more useful for consumers, he wants to point out a math error, which really is a (completely valid to point out is incorrect) terminology error on my part.

So, rather than me telling him he's wrong, he's asserting that I'm wrong, and I'm trying to rephrase to explain my point, but he can't get past the math part. For whatever reason.

Edited, Sep 16th 2013 4:49pm by Smasharoo

I did what? Did I even post in this thread?

To be fair, I don't think Smash argued the math thing after I pointed it out. That was Tricky and someone else IIRC.

However...



That's not true though. I pointed out both that your math was wrong *and* that your argument about the perception effect of mpg versus gpm was wrong as well (or at least why I disagreed with your assertion).

As I pointed out earlier, if we assume you are correct and that people's perception of linear differences in the measurement would cause them to place incorrect weight on relative ratio changes, and our goal is to encourage people to continue to adopt more fuel efficient vehicles, then mpg is actually a better way to express the ratio. You even started out arguing that as fuel efficiency increases, the linear to ratio perception effect would increase (the same mpg increase would appear to be larger than the actual relative ratio change).

What you missed is that this effect actually supports the argument that mpg is a better way to express this than gpm precisely because the perception of improvement stays high even as the actual relative improvement shrinks. Again, assuming we want people to continue to value even relatively small increases in fuel efficiency, this is a good thing.




Except you have failed to even attempt to re-argue your claim that the perception difference between linear value changes and relative ratio changes make gpm a better way to express fuel efficiency than mpg. And it's other people in this thread who can't seem to get past the math issue, not me. I pointed out the math error and then moved immediately to talking about the perception effect even while a couple posters kept accusing me of being bad at math. I kept getting dragged back into that part of the argument, even though I said it wasn't important, and what really mattered is that to whatever degree that perception difference applies, it applies in a way that makes mpg a better way to express the ratio.

Do you still disagree? If so, why? I've already given a couple arguments for why mpg is better. You, on the other hand, simply declared mpg to be a terrible way to do that, then when pressed moved into the math error, and since then have been silent about any additional explanation of your position. So now's your opportunity to support your position Smash. So go ahead!



Edited, Sep 16th 2013 3:19pm by gbaji

Which is the problem. You're not bothering to argue it because in your mind it's already "established" as true. Which is, at the very least, lazy as hell.



Sigh... And, as I said earlier, they do the same damn thing with GPM. The difference isn't whether one creates a different linear perspective relative to the actual ratio difference, but the directionality of that perspective change.




Fine. But what differences? Doesn't MPG make people think they are getting more value at the high end then they actually are? If our objective is to get someone to buy a car with higher fuel efficiency even when that efficiency only saves them a small amount of money personally, and presenting this as MPG instead of some other measure increases the odds that they'll buy that more efficient car, then isn't using MPG exactly what we should be doing?

You're correct that it can create a false perspective of the savings, but in this case, it creates a false perspective that actually increases the likelihood of the behavior we want (assuming, of course, that getting people to buy more fuel efficient cars is what we want). On the flip side, expressing it as GPM makes relative increases in fuel efficiency look smaller to the potential purchaser, and thus will statistically influence behavior *against* choosing to buy a more fuel efficient car.


The fact that's not really debatable here is that if consumers were actually given what you propose we should give them (real total cost of ownership over the expected ownership time period), consumers would be far far less likely to buy hybrid and//or electric cars. We trick them into buying those things by hiding the real costs and presenting them with a semi-false perception of savings in the form of mpg differences. We know that most buyers wont look at the increased cost for a hybrid versus regular version of a given car (for example), and then look at the MPG difference, then calculate how many miles they'll travel in an average year, and how many years they'll own the car, and calculate their savings and realize that they're not actually saving any money (or in some cases actually losing money).

So whether MPG is a good way to express that value or not depends completely on what we want consumers to do. There's no inherent "better" or "worse" method.

Edited, Sep 16th 2013 6:45pm by gbaji

Is that all that's listed on the stickers at the dealerships? In Commieland, we also list average spend/year on gasoline. Consumers get L/100km and the $x,xxx expected to be spent by an average driver each year on gas.

Edited, Sep 17th 2013 6:46am by Uglysasquatch

Smash, I actually agree with what you just said. I was purely speaking about the comparison between MPG versus GPM (or L/100k). IMO, neither of them presents the true cost of ownership very well.

Smash, I actually agree with what you just said

Fuck, really? Then the Lion of Judah as arrived just according to John of Patmos foretold. The Lamb with ten horns and seven eyes is likely preparing as we speak to open the first seal. Make yourself ready!

ITT: "Everyone agrees that having more useful information is better, and that everyone else is wrong"

Unless blind speculation better suits your needs.