Allow me to add this for your consideration. I am beginnng now, here, to promote in every venue and every conversation ( I sell Toyota's, emphasizing the hybrids, and own a Prius II ) that the method for comparing vehicles' fuel economy ratings should be changed to 'GPC' (Gallons per 100 mi).


GPC is not my idea although I have used a similar idea in past comparing different vehicle's fuel economy. GPC to my knowledge is first proposed as a metric for fuel economy in this R&T article which is the subject of this thread. It's elegant and simple. In fact it's the same metric used here for all the vehicles when each reports a tank full.; i.e. No. of galllons and No. of miles. As R&T notes GPC or it's metric version is the normal way economy is measured in the rest of the world as 'liters/100 km'. Until the American public brings itself into the 20th century by adopting the metric system in daily use ( it has been, btw, the official system of measurement for the Federal Gov't since the mid 80's ) we are stuck with outdated, Middle-Ages terminology.

GPC is simply calculated by (dividing Gallons used by miles driven ) then multiplying by 100. It's the same process everyone now uses, except changing the variables ( dividing miles driven by gallons used ). So why propose a change?

Responsibility.

The difference in the two following statements is Responsibility.
'I get 47.2 mpg on average.'
'I use 2.1 gallons every 100 miles I drive'

One is almost a contest encouraging consumption. 'I can go farther than ...' The latter makes me consider what I use to get where I'm going. In addition now there is another readily available statistic which is very important at this time and likely into the future.

How much does it cost me to go 100 miles?

At 47.2 mpg it's not obvious what the cost of this drive actually is. But in using 2.1 GPC it's an easy exercise to see that it costs me about $6.30 at today's prices.

Which brings me to why is the US system of measuring fuel economy still in use whereas the rest of the world uses 'l/100 km'. We in the US have not been perceived as being as personally responsible as the rest of the world in our use of resources. MPG plays into this by making FE a theoretical game rather than a personal commitment. Marketing plays into this as well as certain numbers like '50' and '60' get promoted. One might even envision the fuel providers and the vehicle providers being on the side of maintaining the status quo, albeit for differing reasons.

Challenge: Think about fuel economy in terms of your personal responsibility in using as little as possible.

Herebelow are some easy examples:
Our ICE V6 Highlander uses 5 Gal/100 mi, 5 GPC on average. which is $15/100 mi ( or $2250 / 15000 mi )
My previous 4c Camry's used about 3.3 GPC. which is $10/100 mi ( or $1500 /15000 mi )
My current Prius uses 2.1 GPC. which is $6.30/100 mi ( or $945 / 15000 mi )

I sell SUV's and trucks which use on average about 6 GPC. $18/100 mi

Note also the verb in each sentence describing fuel economy.

Bob Fogarty
kdhspyder

Change can begin with as small a step as refusing to give up a seat on a bus.

Lifetime fuel usage: 2.1 GPC ( 1.99 recent )