Fuel Quantity Per Distance

Thanks for the link.

This is what a lot of us have been talking about for quite some time especially in regards to the Tahoe hybrid. Fuel usage is tricky and doesn't always follow intuition. The fact remains that swapping from a 15mpg vehicle to a 20mpg vehicle will save a lot of fuel, yet swapping from a 15mpg vehicle to a 50mpg vehicle saves even more.

 

U.S. drivers should think in gallons per mile: report - Yahoo! News

Here's the yahoo link. I personally think the best ratio to elucidate how much pain you're enduring would be $/mile.

For simple math purposes let's say hypothetically we're at $5/gallon(next year it's coming, so it won't be hypothetical then). Car A, the prius at 50 mpg would give us 10 cents a mile. Now take a typical midsize sedan Car B which gets 25 mpg. That's 20 cents a mile. Now take a typical supersize 8 cylinder SUV Car C which get's 12.5 mpg. That's 40 cents a mile.

Now over the next 10,000 miles you pay in gas:
Car A $1000
Car B $2000
Car C $4000

Over the next 100,000 miles you pay:
Car A $10,000
Car B $20,000
Car C $40,000

Over 300,000 miles for those who like to drive their cars into the ground
Car A $30,000
Car B $60,000
Car C $120,000

People always like to talk about time it takes to pay back. It depends on the miles you drive. But if you drive 100,000 miles, not only does it pay back, but if you're driving Car C, you've paid more in gas to actually buy Car A free and clear. And if you drive 300,000 miles, you've paid more gas to buy 3 Car A's free and clear.

 

Interesting concept, but probably not as useful as the mpg we normally use. We are used to looking at "18" or "35" miles a gallon, which tells us we are getting better mileage, and thus spending less money, as that figure rises. The "xx gallons per mile" adaptation is understandable only as the number of gallons fall. The example uses 100 miles or 1,000 miles or 10,000 miles. That figure leads to a whole number for gallons (with decimal points here and there). If we stated "5.5 gallons per 100 miles", we also could state ".055 gallon per mile, and most people couldn't visualize the number of gallons used. Again, nice idea, not practical for most of us.

 

And add min/max of PER PERSON. A two seater that gets 50 mpg get less done than a 5 passenger that get 35 mpg.

min: if only driver
max: butts in every seat.

 

The correct metric standard if USA ever grows the kahunas to make the change is litres per 100 kilometres or L/100km.

100 kilometres is used to make the litres whole numbers which people seem to find more friendly. People can cope better reading 4.3L/100km than 0.043L/km, the later looks too scientific and would cause many consumers eyes to glaze over so by using 100km as the base distance a more familiar 4.3L with no additional zeros.
I guess you could use millilitres or cubic centimetres but again this requires a conversion for people to understand as they buy their petrol in litres, well they would if the USA caught up.
L/100km give a nice simple tool to estimate fuel consumption for a trip too. If I leave Adelaide to drive to Melbourne, a distance of about 700km and I know my Prius gets 5.1L/100km on the highway I can do some simple grade 2 maths (7 x 5.1 = 35.7) to work out I will use about 36 litres for the trip.
At 46mpg over the same journey of about 450 miles I need to use grade 3 maths (450/46 = 9.78 gallons)

I don't like the article much though, I believe it is a piece written by a representative of the US auto industry

they tell me by reducing consumption from 18mpg to 28mpg I save 198 gallons over 10,000 miles
And they tell me that reducing consumption from 34mpg to 50mpg saves 94 gallons over 10,000 miles
But nowhere has it stated you will save 355 gallons if you switch from a car getting 18mpg to a car getting 50mpg, why not? That is you will save a further 75% if you make the switch from a toy truck(18mpg) that makes you a man to a Prius(50mpg) that shows you have grown up, rather than a 4 cylinder chev(25mpg) which show you can't think for yourself.
One thing is does highlight, is how stupid H1 Hummer drivers were to buy a car that uses 1,000 gallons of gas to drive 10,000 miles when a turbo diesel Land Cruiser has more room inside and would use only about 20mpg or 500 gallons for the same trip.

And if you would like to know if the site is based have a look at this link I lifted from the site.
Thirsty Hybrid And Electric Cars Could Triple Demands On Scarce Water Resources

 

Same discussion in another thread so I'll cross-post this same reply.

http://priuschat.com/forums/fuel-economy/49419-correct-way-compare-efficiency.html#post649891

We should be changing to a GPC methodology here in the US.