It still does not make sense to me.Dosedmonkey wrote:
grams per mile is super weird in my head, as it is a mix of metric and imperial measurements, but does apparently exsist. Grams per km make more sense.
Grams per Km tells you how much pollutant is created for every Km travelled. Its the same as measuring it in Miles per gallon, or Km per litre, when comparing between different vehicles effects on the environment. As we presume all readings are taken using near identical fuel.
Grams per litre would tell you how environmentally friendly a fuel type was, but not the car. As different cars use different amounts of fuel. One that burns more will obviously create more exhaust, and as such more pollution.
Let's quote what marti had posted:
What unit of productivity?marti wrote: Do you understand the concept of a unit of "work" ?
I thought not.
This measurement system assesses the "costs" of a unit of "work" - where an amount of pollution is a cost of a unit of productivity.
First, when quoting the pollution generated by a factory nobody measures it in grams per widget produced.
Second, ...Joules are units of work. Where are the units of work in this 'grams per mile' result shown in the tables?
Third. If the engine isn't moving, then what? Obviously there is an assumption made somewhere about how many kilometres the engine has moved. Where did the mileage used for the calculations came from? Is there a reliance on information given by manufacturers about a particular vehicle's mileage per unit of fuel?
- I didn't see any mention of the type of fuel being used, only about 'cars', light-duty trucks', 'heavy-duty trucks'.
- marti did not reply to the question about his earlier claim about large SUVs producing less pollution than Dosedmonkey's small car.
A new report reveals that carmakers routinely manipulate official UN-backed miles/gallons tests...
http://www.theguardian.com/environment/ ... ency-tests
U.S. Fines Automakers Hyundai and Kia for Misstating Mileage
http://www.nytimes.com/2014/11/04/us/po ... leage.html
The SI unit of work is the joule. ..... The dimensionally equivalent newton-metre .....
Non-SI units of work include the erg, the foot-pound, the foot-poundal, the kilowatt hour, the litre-atmosphere, and the horsepower-hour.