I think that you are getting hung up with the concept that costs are always measured in terms of money. Sure money is a useful comparator, but sometimes costs are best measured in other units, in this case litres of fuel.
-----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of STANLEY DOORE Sent: 29 January 2008 21:24 To: U.S. Metric Association Subject: [USMA:40300] Re: convenient numerical values Trying to add an independent variable to the nominator in place of km in km/L adds to the confusion and uncertainty since the cost of a L of fuel varies from one fuel station to another while distance is fixed to the L. Stan Doore ----- Original Message ----- From: "Martin Vlietstra" <[EMAIL PROTECTED]> To: "U.S. Metric Association" <[email protected]> Sent: Tuesday, January 29, 2008 1:26 AM Subject: [USMA:40292] Re: convenient numerical values Is it not valid to regard fuel as a currency - if I am comparing my car with your car, I can use £/km, you would use $/km, Han (in the Netherlands) would use €/km but if we used L/km (or L/100 km to generate numbers that are greater than 1), we could all compare the costs of our respective cars. -----Original Message----- From: STANLEY DOORE [mailto:[EMAIL PROTECTED] Sent: 28 January 2008 22:20 To: Martin Vlietstra; 'U.S. Metric Association' Subject: Re: [USMA:40269] Re: convenient numerical values 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 >> >
