Albeit little by little – which is what the market tells us – the hybrid, and in particular the plug-in, that is to say a vehicle charged externally and not simply via the recovery of energy, is becoming a well-established habit for car drivers, especially for the younger generations. Car manufacturers are offering dozens of models, across the full price range, in order to encourage buyers to switch from pure traditional combustion engines.
The hybrid also requires a different way of driving, which, once you have got the hang of it, not only provides a pleasurable experience but becomes a significant way of saving money. The principle which inspires it is linked to the exploitation of the potential efficiency of an electric motor combined with the classic thermal form of propulsion: it is actually during the phases of high mechanical stress, and thus also at peak levels of fuel consumption, that the intervention of the electric component provides the most obvious benefits.
The advantages of the hybrid
Typical cases are standing starts, traffic queues, accelerations and all driving phases which have an obvious impact on the vehicle's fuel consumption. Normally, when starting off and at low speeds, you would prioritise usage of the electric part, resulting in zero levels of fuel consumption and polluting emissions.
The latter characteristic is the one which allows you to enter city-centre controlled emission zones without any problem or to continue driving in locations where traditional-engined vehicles have been prevented from doing so. On the other hand, above a certain speed (this varies from model to model, with a maximum of 50 km/h) or in the event of a more determined acceleration, the traditional combustion engine also kicks into action, as it has the double task of providing the true power and of recharging the battery, even if regenerative braking remains the primary source of re-charge, including for plug-ins.
The ECO zone
What are the secrets to gaining maximum benefit from the hybrid system? The “trick” is to succeed in getting the most out of the combined action of the electric drive train and the traditional combustion one. When moving off, it is best to favour electric power alone, so as to displace the vehicle, at least for the first few metres, with zero fuel consumption.
Once you have reached a speed of 10-20 km/h you can accelerate more decisively, although you need to take care to remain in the ECO zone (generally speaking, a graphical designation shows when you are in this mode) as indicated on the main instrument panel. Once you reach the required speed (the canonical 50 km/h in town, 70 or 90 km/h on non-urban roads and upwards on fast dual carriageways and motorways) it will suffice to ease your foot off the accelerator pedal to bring up the indicator light showing the shape of a car with the acronym EV (Electric Vehicle): our hybrid is telling you that it is ready to travel in electric mode only.
You should once again press down on the accelerator pedal, but this time very lightly and whilst maintaining the needle of the indicator below halfway across the ECO range; in this way the vehicle will use electric power only whilst maintaining its speed, thanks to the so-called cruising feature. Obviously for every model there are different maximum speed limits at which you can achieve this operation: small cars can manage it at around 60-65 km/h, and a saloon or normal SUV at around 70-75 km/h but there are some of the latest generation of vehicles which can achieve it at 90-100 km/h.
The cruising feature allows the driver to travel for over 50% of the drive time with fuel consumption and emissions equal to zero. Driving a hybrid car does not mean therefore going slowly but rather having the good sense to ease off the accelerator once the desired speed is achieved and to anticipate braking phases, keeping these as long as possible, in order to recover more energy. All this occurs with maximum comfort: the silence of the journey and the very function of the hybrid transmission system itself confer a high level of well-being on the occupants, who are cocooned from the impact of city traffic.
The importance of tyres
The efficiency provided by the synergy between electric and traditional traction, however, risks being partially nullified if tyres with a low rolling resistance are not used. The lower the force applied to the tyres, the more fuel you save and the greater the range of the vehicle, especially in the case of the battery pack of a hybrid car. For this reason, Pirelli has developed Elect, a package of various technologies – designed specifically for electric and hybrid vehicles – which are capable of reducing the rolling resistance. In order to drive as far as possible with lower fuel consumption and emissions.