Filed under: Etc.
Maybe you should think in gallons-per-mile instead of MPG
U.S. university boffins have hypothesized that you'll get a better idea of how much you spend on gas if you start thinking in gallons per mile. With U.S. gas prices headed for the upper atmosphere, people are paying more attention to fuel efficiency numbers. Europeans already express their fuel usage in liters/100 km, which makes sense seeing that they've been paying $5 a gallon for much longer than we have.The key is that going from 10- to 20-MPG yields higher savings -- which means less money spent on fuel -- than going from 25- to 50-MPG. The former swap yields $25 dollars in savings over 100 miles, the latter yields just $10 in savings. However, if you know that one car uses 5.5 gallons per 100 miles, and another uses 3.5 gallons per 100 miles... then you immediately know which one will cost you less at the pump.
Of course, this all depends on what kind of car you're starting with in the first place. Researcher Richard Larrick said, "We were trying to decide whether to get rid of a minivan and go for a station wagon versus getting rid of a sedan and going for a really high-mileage hybrid car. We realized in the end we were better off trading in the minivan and only gaining 10 miles per gallon then we would be trying to swap out the sedan for a highly efficient car." Thanks for the tip, Stephen!
[Source: Reuters]
Reader Comments (Page 1 of 5)
Andrew 4:12PM (6/21/2008)
"However, if you know that one car uses 5.5 gallons per 100 miles, and another uses 3.5 gallons per 100 miles... then you immediately know which one will cost you less at the pump."
Ummm... what? Everyone knows that higher MPG will cost less at the pump. The minivan-for-wagon versus sedan-for-hybrid scenario is interesting, but you still have to crunch the numbers to find out what the real savings will be, regardless of which is the numerator and which is the denominator.
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The Talking Hamburger 5:06PM (6/21/2008)
I think using this 'gallons per mile' has merit for illustrating a better sense of money savings. It puts the emphasis on the least amount of fuel one would have to buy to travel the same distance. This could prove useful in deciding how much utility you'd be willing to sacrifice Like the example of choosing amongst a station wagon or a small hybrid to replace a minivan, you don't necessarily have to go to an extreme to get the same use.
SimbaDogg 5:42PM (6/21/2008)
yeah, seriously...
going from mpg to gpm...dumbest thing i've ever heard of in my entire life. why would u even compare the two, theres a 100% correlation between the two
why not the LS2LS7? 5:44PM (6/21/2008)
This proposed system does help you understand your savings better. But it hurts you ability to understand your range on a given amount of fuel.
I think optimizing our system to help people keep from running out of gas is at least as important for optimizing our system to help people understand how much money they'd save on fuel costs.
kballs 1:25PM (6/22/2008)
What's REALLY funny is that they're calculating all these numbers like some pro mathematician and yet fail to realize that you can't save money by buying a new car no matter how much gas it saves (unless you were going to buy one anyway to replace a dying one). If you already have a perfectly good vehicle, you have to factor in the purchase price of the new car to calculate total per-mile cost (which is almost always higher for the new car - even a 50MPG+ one - unless you're swapping a high value car for a low value car).
People don't think like this though... it's all about singular dimensions: MPG, $/gallon, monthly payment, or cost to fill the thank (no matter how often you have to fill it), but never total cost/mile.
Andrew 4:18PM (6/21/2008)
Okay, I think I understand what they're saying. For example, minivan-versus-wagon saves me 2 gallons per 100 miles. sedan-versus-hybrid saves me 1 gallon per 100 miles. It's easier to tell right off which is more significant. Assuming both are driving the same number of miles. But, one driver in the home may go a lot farther each day, so putting dad in a hybrid rather than mom in a wagon may actually save more MONEY overall because even though it's less of a relative savings per 100 miles, if he drives twice as many miles, it still saves the most money. I guess it's an interesting concept, but I maintain you have to do a little more work to really make such a decision.
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Parkerman 4:30PM (6/21/2008)
I dunno.. I'm still pretty confused.. I'm not really understanding the point of the article... Maybe I'm just really tired.
Johnny 4:21PM (6/21/2008)
This is long overdue.
For those that dont get this read the story again. If you still dont get it do some scenarios in your head.
Gallons per 100 miles may sound complicated at first but once implemented it is a very accurate indication of what your savings will be on your commute.
For example you drive 100 miles to work and back. If your truck goes 6 gallons per 100 miles you know 6 time 4 you spend 24 bucks every day.
Under the current scenario you take the 100 miles then you look up the truck milage of 16.5 mpg. Then you divide 100 by 16.5. Then you multiply that by 4 bucks and get 24.
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Parkerman 4:37PM (6/21/2008)
I would still rather know the MPG rather than gallon per miles.
I mean, 100 is a nice round number.. what what if your daily commute is like.. 113.7miles.. or something just oddball.
I like to know.. Hey.. I can go 25 miles on 1 gallon of gas.
spookthehamster 4:44PM (6/21/2008)
@Parkerman
You'd multiply it by 1.137.
g/100m or l/100km makes so much more sense
Parkerman 5:00PM (6/21/2008)
@spookthehamster
and how is that any different than dividing it by your mpg?
Matt 5:53PM (6/21/2008)
@spookthehamster
Or you can NOT BE A RETARD, and take the Miles Per Gallon of your vehicle and do it in your head, the way people have done it for one hundred years, and have it be the exact same result as this ridiculous BS.
tankd0g 4:37PM (6/21/2008)
Or you could just all go metric and get on the L/100km bandwagon with the rest of the world. I'm getting tired of dividing Autoblog stories by 3.785 anyway.
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Vik 4:55PM (6/21/2008)
I totally agree with you.
notYou 5:28PM (6/21/2008)
Maybe then, you should also start writing in Mandarin Chinese (the most widely spoken language on the planet) like the rest of the world instead of writing in stupid English. You know, they get tired of translating your stupid comments.
Soul Shinobi 5:24PM (6/21/2008)
Amen.
adrenalnjunky 8:20PM (6/21/2008)
@notYou
I was going to argue that point - I was googling the populations of the USA, UK, and Australia, figuring English was more common a language, or even possibly Spanish. I know that China has roughly 4 times the population, but I figured that the population wasn't spread out enough to be considered "Widely Spoken". Then I googled "Most common language" and Widely spoken language" and was proved completely wrong. I even had to erase the post I was writing to write this one.
Thanks for enlightening me.
P.S. - English and Spanish swap between # 2 & 3 depending on what websites you're checking.
Kingus 8:22PM (6/21/2008)
"I'm getting tired of dividing Autoblog stories by 3.785 anyway." but that wouldn't give you L/100km.
To convert between the two just divide 235 by MPG for L/100km or divide by L/100km to get MPG
tankd0g 12:31PM (6/22/2008)
Sorry, English still rules the world for now. You don't get to fly a 747 into an international airport by speaking Mandarin.
cheezwiz 9:23AM (6/23/2008)
Or you metric folks can just learn to think of numbers besides 10 and then the English system works just fine. All the metric system does is make you lazy at arithmetic.
That's just what we need - more people that don't bother to do arithmetic. Then, we just end up with more pointless articles like this one...