Vehicle Fuel Consumption

=== by Bob Sutherland ===

This web page contains a collection of charts for converting between various fuel consumption rating scales for vehicles.

When you visit a car or truck dealership in person or on the Internet you are likely to be offered a chance to read a long list of technical specifications for any vehicle you may be interested in buying. One of those technical specifications will be the fuel consumption rating. The fuel consumption rating may be called the fuel economy rating or fuel efficiency rating. In Canada there are usually two numbers listed, one for city driving and one for highway driving.

During my lifetime I have encountered four different fuel consumption measuring scales being used by the automobile and trucking industry. Each measuring scale uses different units. Here are the four scales:

km/L = Kilometres per Litre
mpg (Imp.) = Miles per Gallon measured using Imperial gallons
mpg (U.S.A.) = Miles per Gallon measured using United States liquid gallons
L/100 km = Litres per 100 Kilometres

The fourth item of litres per 100 kilometres is a measuring scale that is quite different from the others. This is the only one of the four scales where smaller numbers mean better fuel economy. It is the only measuring scale that is plotted as a curved line rather than a straight line on a distance travelled versus liquid volume of gasoline consumed graph. The litres per 100 kilometres measuring scale exagerates the difference when comparing vehicles with poor fuel consumption ratings. At the opposite extreme the measuring scale tends to become obsolete and meaningless as the fuel economy of vehicles improve.

With four different vehicle fuel consumption measuring scales there is obviously a need for a simple way to convert and compare measurements. A person could go on the Internet and find a website with a conversion calculator. The problem with a calculator is that you only get to see one answer at a time. If you make a typing mistake while entering a number you might not realize it and get a wrong answer.

I have instead taken the approach of creating long lists of equivalent measurements. You can scroll down the lists, find the number(s) you are searching for and see the equivalent value(s) of the other scales listed beside it.

The following web pages contain long lists for converting between the vehicle fuel consumption measuring scales. Please read carefully and pick the web page that best meets your needs.

The following five lists perform a simple conversion between two measuring scales. These are your best choices if you are using a cell phone or mobile device with a narrow screen.

km/L → mpg (Imp.): Convert kilometres per litre to miles per gallon measured using Imperial gallons.
km/L → mpg (U.S.A.): Convert kilometres per litre to miles per gallon measured using United States liquid gallons.
mpg (U.S.A.) → km/L: Convert miles per gallon measured using United States liquid gallons to kilometres per litre.
mpg (U.S.A.) → mpg (Imp.): Convert miles per gallon measured using United States liquid gallons to miles per gallon measured using Imperial gallons.
km/L → L/100 km: Convert kilometres per litre to litres per 100 kilometres.

The following four lists convert between three measuring scales.

km/L → mpg (Imp.) → L/100 km: Convert kilometres per litre to miles per gallon measured using Imperial gallons to litres per 100 kilometres.
km/L → mpg (U.S.A.) → L/100 km: Convert kilometres per litre to miles per gallon measured using United States liquid gallons to litres per 100 kilometres.
mpg (Imp.) → mpg (U.S.A.) → km/L: Convert miles per gallon measured using Imperial gallons to miles per gallon measured using United States liquid gallons to kilometres per litre
mpg (U.S.A.) → mpg (Imp.) → km/L: Convert miles per gallon measured using United States liquid gallons to miles per gallon measured using Imperial gallons to kilometres per litre.

The following three lists convert between all four measuring scales. Each list starts with a different measuring scale to begin the conversions. These conversion lists are best viewed on the wide display of a computer screen.

km/L → mpg (Imp.) → mpg (U.S.A.) → L/100 km: Convert kilometres per litre to miles per gallon measured using Imperial gallons to miles per gallon measured using United States liquid gallons to litres per 100 kilometres.
mpg (Imp.) → mpg (U.S.A.) → km/L → L/100 km: Convert miles per gallon measured using Imperial gallons to miles per gallon measured using United States liquid gallons to kilometres per litre to litres per 100 kilometres.
mpg (U.S.A.) → mpg (Imp.) → km/L → L/100 km: Convert miles per gallon measured using United States liquid gallons to miles per gallon measured using Imperial gallons to kilometres per litre to litres per 100 kilometres.