Drust evaluates your use of the accelerator, the gearshift and on how you anticipate in order to calculate your driving score. 

When you fill up your car, some of the energy contained in the fuel is converted into mechanical energy, the rest is transformed into useless heat! The efficiency is the ratio between what can be recovered usefully by the engine and what has been spent in energy. 

Contrary to preconceived notions, do not hesitate to press the accelerator while making sure to always stay at low engine speed (<2500 rpm in diesel, <3000 rpm in gasoline) to have the best efficiency.

The drust solution helps you, through its indications, to enter and stay in the optimal efficiency range.