You are driving a car with a plug-in hybrid drive system. How can you optimise fuel consumption?

You answered correctly. To optimise fuel consumption in a plug-in hybrid, it is important to regularly charge the battery from an external mains supply and to make use of the electric drive through your driving style. This allows you to drive more on electric power, reducing the use of the combustion engine and overall fuel usage. Only using recuperation (regenerative braking) to charge the battery is not sufficient, as it cannot restore as much energy as mains charging. For best efficiency, always keep your battery charged and use electric driving whenever possible.