You may need to translate the fuel consumption of a vehicle for the translation of any type of text, technical or not.

Standard usage

Clearly, in English fuel consumption is not expressed in the same way as in French. It is typically a situation that is not about translating words but adapting your content and finding an equivalent according to French usage.

Indeed, your English text will show mpg: the distance (in miles) per gallon (the unit of measurement for liquids).
Yet, French usage is to give l/100 km:  the number of litres (unit of measurement for liquids) for a standard distance of a hundred kilometres.
This shows that the concept of fuel consumption is looked at from a different angle depending on the language that is used.

What does this mean for the translator?

This means that the translator will need to apply two methods simultaneously: a conversion (from miles into kilometres and from gallons into litres) and an inversion (one of the solutions for what is called a metonymical modulation).

Should the point of view not be inverted, the end-reader will not actually understand the fuel consumption.
A French mind is used to expressing fuel consumption in l/100 km and will not grasp it if expressed the distance covered per liquid unit, even if miles have been converted in kilometres and gallons into litres. That’s why it is essential to invert the concept.

Conversion table mpg into l/100 km
As a guide, here is a mpg to l/100 conversion table with numbers truncated to the first decimal because it is the way the information is usually given in French.

The conversion table includes two rows for mpg with different results in l/100 km. One uses the British or Imperial gallon and the other the American gallon because, yes, gallons are different on each side of the Atlantic (or it would have been too simple!) 😉

There you are! You now have the tools to give a good translation of fuel consumption from English to French! Congratulations! 🙂