Friday, March 20, 2009

Silly comparisons

Of course, there are also some other problems that come out in the publication. The article on the right states:
The original 1908 Model T sported wood wheels and a fabric roof and could sputter up to 45 miles an hour. The typical SUV of today takes less than 10 seconds to hit 60 m.p.h., even as it weighs four times more.
Notice that the opening paragraph sets up a strawman right from the get-go. The Model-T is portrayed as quaint ("sported wood wheels") and obsolete ("sputter up to 45 miles an hour"), even spelling out "miles an hour", like spelling out an acronym is old-fashioned. On the other hand, the SUV is portrayed as being able to reach a speed that far-exceeds what the Model-T did, and in "such little time", even though SUVs are much heavier. Of course, the entire first paragraph says nothing about the topic of this blurb: "Fuel-efficiency myth".

On the Freep website, Hyde continues with the following:
What remains unclear is how it makes sense to compare a fabric-roofed, four-seat car to a seven-passenger truck stuffed with high-tech accoutrements.
Ummm.... Well, that's pretty easy. You take a popular car model/type from 1908 (a Model T) with one from 2008 (SUVs). The point of comparison is not what the "accoutrements" are in the Model-T vs the SUV, but that after 100 years, one would expect a little bit more improvement. This comparison also tacitly touches on the question of, "How did we get here?" with "here" being a street culture, trucks getting bigger, commuter villages, and comfort over utility (especially in the so-called sports utility vehicle). Of course, this point is a place where Hyde could have taken the road less-traveled in Detroit: to question the status quo of motor vehicle ownership, the car-culture, etc. ... but no. Hyde concludes with the following amazing piece of logical discontinuity:
When adjusted for their massive differences in weight using the government’s formulas, today’s typical SUV is about five times more efficient than the Model T.
Hyde, there is a difference between comparisons on paper, where you can do this sort of mathematical simplification, and the physical world, where net fuel economy is the major point of contention; the thing that impacts real people. Who cares that today's SUVs are 5x more fuel efficient if you normalize by weight? What Hyde is saying is that a Model-T's fuel economy is 80 pounds/mpg, while the average SUV's fuel economy is 255 pounds/mpg. Although this is mathematically correct (if you divide through by the values given in the article), the concept of measuring fuel economy as pounds/mpg is laughable. Laughable because if you did this sort of comparison with the expectations of the 2010 model Toyota Prius:

Weight: 2975 pounds
Fuel economy: 50 mpg
2975 pounds/50 mpg = 59.4 pounds/mpg

Oh my god! The SUV has a better Hyde fuel economy than a Prius! Can you believe it!!! WOW! The "average" SUV has a fuel economy of 255 lbs/mpg, and the 2010 Prius is only 59.4 lbs/mpg. Hell, even the Model-T has a better Hyde-fuel-economy at 80 lbs/mpg! Those damn lefties tree-huggers making negative claims about SUVs...
Oh, wait... That doesn't make sense!!! A unit like lbs/mpg is as useful a measurement of fuel economy as GDP/CO2 is a measurement of CO2 emissions.

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