The fuel efficiency (km/L) is the governing factor. Prices are given in
cost/L or cost per gallon in the US. Therefore the cost per L determines
the best buy regardless of distance. Also, L is in the denominator in both
cases. The assumption that price is the same at different fuel stations is
not valid.
Stan Doore
----- Original Message -----
From: "Martin Vlietstra" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>; "'U.S. Metric Association'"
<[email protected]>
Sent: Monday, January 28, 2008 4:49 PM
Subject: RE: [USMA:40269] Re: convenient numerical values
If one trader sells apples at $1.00/kg and another at $1.20/kg, which is
the
more expensive? The one with the larger number associated with it.
Similarly, if one car uses 5 L/100km and another uses 6 L/100km, which is
the more expensive? Again, the one with the larger number associated with
it.
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf
Of STANLEY DOORE
Sent: 28 January 2008 18:55
To: U.S. Metric Association
Subject: [USMA:40269] Re: convenient numerical values
The use of km/L is similar to the mpg used in the US. It avoids the
need for a decimal point in L or the use of mL in the L/km expression..
If one runs out of gas and you know the distance you need to travel to
the next fuel station, it's very easy to know how many L are needed.
Stan Doore
----- Original Message -----
From: "Pierre Abbat" <[EMAIL PROTECTED]>
To: "U.S. Metric Association" <[email protected]>
Sent: Monday, January 28, 2008 7:11 AM
Subject: [USMA:40258] Re: convenient numerical values
On Sunday 27 January 2008 20:37, Ziser, Jesse wrote:
I'd like to offer another possible example of violation of the rule of
thousands. I keep seeing L/100 km in fuel efficiency contexts. I also
occasionally see km/L but it appears to be rarer. km/L is clearly more
"thousandy", and also has the debatable advantage of being "distance per
volume" just like MPG. Besides, "L/100 km" seems an awkward mouthful.
Is
this really the preferred unit?
I'm thinking about getting metric mileage bumper stickers for my friends
and family (most of whom I'm sure would enthusiastically accept and
display
them) and I was wondering if anyone had any other opinions on the km/L
versus L/100 km issue. I've been unable to find much about it online.
At least two of us agreed, the last time this came up, that the unit of
fuel
consumption should be the liter per megameter, or microliter per meter
(or
cubic millimeter per meter if you wish to avoid "liter").
As to methods of averaging, the harmonic mean is a bit more abstruse than
the
arithmetic mean, but it comes up all the time in electric circuits. Every
little kid should know some reciprocals and be able to estimate a
harmonic
mean.
Pierre
