Gallons/100 Miles (now provided by EPA)

Litres/100 kilometres, the world understands that.

 

I think that should be 28 gm of prevention worth .45kg of cure.

 

Yes, but it also drives 50 miles for each gallon USED Especially good to know when fuel is sold $/gal

 

Here, in the whole European Community, we're used to litre/100 km rate. And a difference in 0.5 litre every 100 km means a lot for a new car. It's a matter of been used to measure, not the measure used (I have a slight feeling that my english is betraying me again

But, given this, I find a wreck taste for the km per litre rate -or MPG when reading here- and I like to use my spreadsheet with all possible conversions.

 

You are exactly correct. When it comes to using a measurement for everyday use, familiarity is very important. As an engineer, you can give me a measurement in any equivalent units and I'm happy, but I will probably have to run a conversion before I get a gut feeling for the figures.

This was the trouble we had back in the 1960s when the USA tried to switch over to the metric system. People were not comfortable with the units, so too much time and effort was spent on conversions. If we had just switched and been done with it, people would have rapidly adapted from everyday use.

Tom

 

Your english is fine

The issue is that the USA would not use liter / 100 kilometer but instead use gallons / 100 miles. Both are much larger units so savings are a smaller decimal place.

1 L / 100 KM = 0.42 Gal / 100 miles

So a reduction of 0.5 L/100KM is much smaller for Gal / 100 miles. People would get used to it in time but for many it would take a long time to fully understand the difference in their head without calculations.

(Personally I think the USA should just use Liter / 100 Kilometers like the rest of the world AND fully convert to the Metric system by 2015)

 

I think we should use hogshead per furlong.

Tom

 

I agree the two methods are different expressions of the same results. And I am opposed to melding a company's various MPG ratings for the purposes of promoting either high-mileage or low-mileage cars for CAFE purposes. I also am opposed to CAFE standards and meddliing of government in private enterprise. But it is a common form of expression to say MPG and "everyone" understands what is being said. Why would the federal government bother to change the expression except to make some bureaucrat feel good about his job?

 

Exactly. You have a good idea what 32F is right away, or how large in your mind a 2x4 is instead of a 5cm x10cm. When you grow up with it, you have a certain feel for the numbers.

 

When I worked for the "low tech" truck manufacturer, we did all of our drawings in mm, but all of the fasteners were SAE inch measurements so there was a lot of converting (3/8" ~ 10mm, 50.8mm = 2 inches, etc).

When I worked for the "high tech" electronics manufacturer, all of the dimensions were in inches or mils (thousandths of an inch). Go figure.

 

US or UK hogsheads?

 

I used to have no feel at all for L/100 km but since getting my Prius with it's MFD feedback screens I've now got me head around it quite nicely.

I hope most cars will have this feedback soon which can help train the populace, provided that both units are available/ can be used on screen.

 

I have two thoughts on this:

1) When I bought my Prius, I wanted to double my gas mileage, over my old car. It got 26 MPG, so I'd been aiming to get 54 MPG, lifetime in the Prius. But now that I look at things "upside down", using GPC, I actually have an easier target to hit, 52 MPG (26 MPG = 3.846 GPC; 3.846/2 = 1.923 GPC = 52 MPG). And it hit me, that just because I can go farther on a gallon of gas, doesn't mean that I need to drive more miles. I just use less fuel to drive as far.

2) The real advantage in using MPG, is in not running out of gas on a trip. If I've put 2 Gallons in the tank, & if I can get 52 MPG, I know I can go 104 miles (2 * 52). But conversely, If I know I'm going to drive somewhere that's 140 miles away, and I'm getting about 1.92 GPC, Then I'll need 2.7 gallons of gas (1.92 * 140/100).

And to those pushing for L/Km, I say that's great, as long as you change ALL the road signs, mileposts (Kilometerposts?), speed limits, & gas pumps and provide a way for drivers of older cars to fix there speedometers. You really need to do it all at once. If Obama intends to make public works money available for roads, this would be the time to do it. Otherwise, I'll keep using my old familiar units...

 

It is true that the conversion to the SI units will be difficult for those that have grown up with the US system but we still need to do it. Every country in the world except the US, Myanmar, and Liberia uses SI units. We are simply at a disadvantage in a global economy if our people can't use the system of measure the everyone else uses.

Currently we a hybrid system were businesses use SI units but individuals use US units, our food is dual labeled both in SI and US unit, etc.

Our bungling with SI units can be embarrassing and costly to. NASA lost a $328 million Mars probe because someone screwed up a conversion from US units to SI units: [ame=http://en.wikipedia.org/wiki/Mars_Climate_Orbiter]Mars Climate Orbiter - Wikipedia, the free encyclopedia[/ame]

 

Aren't the speedometers already marked in KPH, in smaller numbers inside the MPH ring? At least, every car in my household is -- model years 1986, 1989, and 1997.

 

Yes, I remember that Mars fiasco. Yes, it certainly would be great if a 100% used the same scales, preferably from birth
But, when you are used to one, 55 looks different from 88, even if it they are the same speed A comfort level, something to gage things by. And, as you pointed out, it has is costs, at times, huge ones.
At one time in my life I used the SI, then converted for a very long time, now it would be strange to change again, certainly not impossible, just that constant recalc.

 

Do you think when Australia bit the bullet and switched to metric anyone understood the system?
Change is hard but sometimes it is eventually for the best. My comment was that the USA need to get with the program, and the UK need to get over their half arsed switch over and change to kilometres. They have done the litres switch but still drive miles???

 

The actual global standard unit for fuel consumption is litres per 100 kilometres. Australia made the change back when I was in highschool, isn't it about time the USA caught up with this backward little nation of (at that time) under 17 million? It can be don but wont be if you never make a start.

Even my 81 year old dad told me his new car's expected fuel consumption was 6.2 litres per 100 kilometres just after he got it. My dad still stated prices in pounds shillings and pence, we dropped that system in 1966!

(Dad passed away 01/03/2009 For you people who mix the order of the date up that is 01 March 09)

 

Personally I track my GPM (gallons per month). Went from 48 gpm in 2005 to 15 gpm two years later. (Found a closer, better job, and bought the Prius).