5. Fuel consumption measurements

This section presents the various technologies used to measure engine fuel consumption, whether installed on a test bench or in a vehicle. The three main methods used are :

• volumetric measurement ;

• mass measurement ;

• global or instantaneous flow measurement.

Volumetric measurement is historically the oldest.

Measuring the fuel consumption of an internal combustion engine is one of the fundamental quantities required for fine-tuning thermal machines. The measurement principle is based on flowmetering, but requires a high degree of accuracy, of the order of 10 ^–4 , to enable precise efficiency calculations.

For a long time, this measurement was carried...