Converting MPG into liters per 100 km

<div class='quotetop'>QUOTE(ckbarnard @ May 2 2006, 09:31 AM) [snapback]248448[/snapback]</div>

http://www.eforecourt.com/l_100km_mpg_convert.htm

http://www.pege.org/fuel/convert.htm

http://www.4wdworld.com.au/tipstricks/fuelconv.htm

...

 

It appears that the formula to convert between miles per US gallon (MPG) and liters per 100 km (l/100km) is approximately 235.2 / x . The same formula converts in both directions. Beware that there is a difference between US and imperial gallons. Some tables, such as the Australian one above, use imperial gallons.

For whatever it's worth I believe that l/100km is a much better way to measure efficiency. Being the inverse of MPG, it makes the differences in inefficient cars more apparent.

 

My last car had a metric converter button that changed more than just the speedometer. It changed the odometer, temperature, average economy and instant economy. I didn't need that, but it was fun on occasion to use it.

 

<div class='quotetop'>QUOTE(ckbarnard @ May 2 2006, 03:31 AM) [snapback]248448[/snapback]</div>

Here's what I use (figures rounded);

1 mile = 1.6KM
1 US Gallon = 3.78L


The following Excel formula should convert from US MPG to L/100km


=(3.78/((MPG*1.6)/100))

Or to convert L/100KM to MPG US

=(62.5/(L100KM/3.78))


The bold of course being the number or cell reference you want convert. I think that math is right...

Of course, you can replace the mile/kilometer conversion and L/US Gallon conversion with the more scientifically precise numbers.

Kevin

 

Google calculator can help you too, it does it all. I heart Google.

http://www.google.com/help/features.html#calculator

 

<div class='quotetop'>QUOTE(Sarge @ May 2 2006, 09:44 AM) [snapback]248596[/snapback]</div>

Thanks I am going to add L/100km and Gal/100 mi to my spread sheet. I should be interesting to follow!

 

Most contributors to this forum reside in the USA and use mile etc. When an author refers to figures I have to convert each to metric for the articles to make sense because I live in a country that uses metric. Either I need a good memory, a mathematical brain or use one of the conversion sites mentioned above to do the conversions.
The first two options are impossible and the last tiresome - too many conversions.
Has anyone designed a table that I can print out and refer to for conversions? To cover most occasions it would need to have miles per gallon to litres per 100 kilometres as well as MPH to Km/h.

 

this is the one I use
http://www.packexpo.com/education/ref/fuel_conv_cal.shtml

 

Someone mentioned the Google Calculator. The simplest way of using it is to simply type your desired conversion into the usual search field. E.g., type "42 mpg in liters per 100 km" (without the quotation marks) and in an instant you will get the reply "42 miles per gallon = 5.60034725 liters per 100 km".
Or vice versa, "4.9 liters per 100 km in mpg" will give you "4.9 liters per 100 km = 48.0029764 miles per gallon".

Incidentally, you can use the same trick for money or any unit conversion:
"26500 usd in gbp" yields "26 500 U.S. dollars = 14 160.5215 British pounds"
"6 feet 2 inches in m" yields "6 feet 2 inches = 1.8796 meters".
Etc.
Olle
(New member. From Sweden.)

 

And for all fellow scientists/pilots amongst us that would like a rule of thumb as well as a reasonably precise graph, here's my take on this conversion task:

http://prius.inside.net/mpg2lp100km-midres.png

 

Use Google:

you simply type your conversion into the search box. Here's an example:

convert 50mpg to litres/100km

and it returns

50 mpg = 4.70429169 litres / (100 km)

voila!

This works for temperatures,weight...anything. Very clever.

 

<div class='quotetop'>QUOTE(floydenheimer @ May 2 2006, 01:03 PM) [snapback]248609[/snapback]</div>

Ditto

Example: 55.5 mpg in liters per 100 km

Example: 4 liters per 100km in mpg

 

235.2/x = y;

Magically, if x is MPG then y is l/100 km and
if x is l/100 km then y is MPG.

The constant has units (miles*liters)/(gallons*(100 km)).

In other words, when you multiply MPG with its corresponding l/100 km, you get this constant value 235.2.

Remember the basic electric calculations? I learned them with pie charts.

One had the top half as volts (V) with one bottom quarter being current (I) and the other being resistance ( R ). You cover the one you want with your finger and have the formula for calculating it. So,

V = I*R, R = V/I, I = V/R.

Similarly, Power (P), Voltage (V) and Current (I) have the same relationship.

 

I assume the US Prius displays mpg using US Gallons. Does the UK Prius show MPG or l/100km? When I rented a car in the UK, I noticed that speed and road markings are miles etc, but you buy petrol per litre.

Does the UK Prius do both? If it displays mpg does it use imperial gallons?

This is why your Mars orbiters don't get there you know....

http://edition.cnn.com/TECH/space/9909/30/mars.metric.02/

 

<div class='quotetop'>QUOTE(deh2k @ May 2 2006, 07:13 AM) [snapback]248494[/snapback]</div>

Ina prius? Not really! I have a 2007 Prius in Costa Rica... It shows l/100km... But the consumption graphic looks inverted as yours! the X axix is the same... the last 30 minutes in 5 minutes splits... but the Y axix goes from 0 (bottom) to 10l/100km (top) (infinite miles per gallon to more or less 23 MPG)... yours shows from 0 to 100 MPG, so basically you have the whole range there!!! For me... if the bar is small it means great savings (I try to drive in a way that the bar stays lower than half way (5l/100 Km)) a big bar means... mor gas consumed... but you never know how bad it was... since the maximum it grows is 10l/100 km.
For you... the bar goes from 0 to 100 MPG, and a small bar means more gas spent (235l/100km) to 2l/100km...

In wife's Citroen C4 2007 You can choose to use MPG, KPL, or l/100km and everything changes... from speedometer to odometer... to miles, or kilometers!

Funny Fact: In Costa Rica is a common trend from dealerships to use Kilometers per Gallon (yeah that's right!!! KPG!!!!) the reason is that using a small distance measurement divided by a bigger volume measurement result in bigger numbers.... so is very common to hear than a car makes over 100 kPG!!!!

 

My favorite converter.
http://www.tdiclub.com/misc/conversions.html

I have never seen a 5 minute bar taller than 8L/100km
In England you buy fuel in litres but all the speed limits and distances are measured in miles! Speedos are in mph.
I don't know how they put up with it.

 

<div class='quotetop'>QUOTE(Marco CR @ Oct 13 2007, 02:52 PM) [snapback]525232[/snapback]</div>

Which is why I like to think of of my mileage in inches / acre-yard

I'm getting 51 mpg (I live in SoCal and I'm new at this), or 262,216,891,520 inches / acre-yard!