Hybrid car: how it works, advantages and disadvantages

The "classic" hybrid car, also known as a "simple hybrid" or "full hybrid", remains the best known of the cars with alternative engines. Popularized by Toyota, this technology has become more democratic. Automobile-Propre explains how it works and what its interest is.

Since the launch of the very first mainstream hybrid car in 1997, the famous Toyota Prius, technology has evolved and spread. It has democratized the idea that energy other than oil can power our cars. and to slightly reduce our consumption and CO2 emissions.

What is a hybrid car?

Before knowing how a hybrid car works, it is important to know the definition of a hybrid car. A hybrid car has two engines on board, a combustion engine and an electric unit.

They can be articulated differently depending on the hybrid technology developed by the manufacturer. A conventional hybrid car allows you to consume no fuel below 30 to 50 km/h when the battery level allows it.

In a traffic jam, in a "Zone 30", manoeuvring in a car park, the combustion engine is no longer supplied with fuel but drives the wheels thanks to the integrated electric motor.

When it comes to how a hybrid car works, we can divide simple hybrids into two categories. The first relies more on the combustion engine, while the second relies mainly on electric power.

How does a hybrid car work?

On the vast majority of models, the petrol engine drives the wheels with the help of the electric motor under certain conditions. The electric can act on its own, mainly at low speeds.

A small-capacity battery provides the electricity needed for its operation. It can be placed under the floor, the rear seat or in a part of the trunk. It is automatically recharged during braking and deceleration phases thanks to the vehicle's inertia. We can talk about a "self-charging" hybrid.

Hybrid cars also work the other way around, such as the Honda Jazz e:HEV. This has a combustion engine which, at low speed, is only used to produce energy that will be stored in the battery. This powers the electric motor, which is responsible for propelling the vehicle.

The combustion engine then works like a generator: by rotating in a vacuum, it produces electricity that is stored. Some models use a separate generator or a starter-generator.

At high speeds, the combustion engine and the electric unit work together to offer the best compromise. However, recent hybrid models can be driven in all-electric mode at speeds of up to 90 or 100 km/h. Over very short distances and in optimal conditions (downhill for example), the combustion engine can even cut out at up to 130 km/h on the motorway.

At Nissan, with the Qashqai and X-Trail ePower, the petrol engine only serves as a generator, it never drives the wheels. But since these models cannot be plugged in, they are still considered classic hybrids.

There are also plug-in hybrid vehicles with a larger battery capacity, which can be plugged into a power outlet to charge. On the other hand, non-plug-in hybrid cars do not need to be plugged in. Where hybrid cars only offer a maximum of 2 to 3 kilometres of all-electric power, a PHEV car can offer several dozen kilometres of range in 'zero emissions' (most often at least 50 km).

Is it profitable to buy a hybrid car?

There are therefore several types of conventional hybrid technologies that distribute the effort differently between the combustion and electric engines and use specific transmission systems. It is also what will define the saving capacity of an engine.

The simple hybrid powertrain will be of real interest in urban driving, where the electric powertrain is capable of providing a good part of the kilometers. For its Clio hybrid, Renault says that you can drive 80% of the time in electric mode and reduce your fuel consumption by 40%. In peri-urban areas, consumption will also be reduced, even more so with some eco-driving concepts. Taking your foot off the accelerator pedal earlier when approaching a roundabout fills up the battery.

Regardless of the technology in detail, classic hybrid cars are among the most affordable alternatively powered vehicles. The additional cost compared to a non-hybrid model is around €3000 in the catalogue. It is possible to significantly reduce this gap thanks to the promotions regularly offered by manufacturers.

In June 2023, the Toyota Yaris Hybrid was offered from €23,950 while its non-hybrid version starts at €20,200, but with less power. On the Renault side, the Clio E-Tech is available from €23,050, compared to €20,400 for the petrol version in a similar trim. But the gap narrows when you take into account that hybrids are equivalent to an automatic gearbox.

It should be noted that classic hybrid cars are no longer entitled to the ecological bonus. However, they may be eligible for the conversion bonus. If you often drive in the city or in urbanized areas, the additional cost of the hybrid can be paid for with the gain in consumption.

What are the advantages of the classic hybrid car?

• Reduced fuel consumption (between 3.8 and 4.3 l/100 km for a Yaris Hybrid compared to 5.6 l/100 for a non-hybrid Yaris in the WLTP combined cycle).
• Use of kinetic energy from braking and deceleration, which is wasted in 100% combustion vehicles.
• Saving brake pads thanks to regenerative braking.
• Driving comfort in the city at low speeds (silence, fluidity of propulsion, ease of manoeuvres).
• Low maintenance (automatic or variable gearbox, motor running at ideal speed and relieved by the electric motor)
• Longer lifespan than a conventional combustion engine vehicle (no manual clutch, less stressed petrol engine and regulated by the on-board computer).
• Presence of a Crit'Air 1 sticker

What are the disadvantages of the classic hybrid car?

• Slightly higher purchase price than a 100% combustion model (additional cost varies depending on the offers and the manufacturers, between 1500 and 5000 €).
• Low battery capacity, which only allows electric driving at certain times automatically selected by the on-board computer (usually at low speeds).
• Exclusive use of petrol as primary energy. A hybrid car is above all a combustion engine, it is content to recover energy usually wasted during braking and deceleration. It is not possible to plug it in and therefore choose the origin of the electricity consumed on board, unlike a plug-in hybrid or 100% electric car.
• At high speeds on the motorway and on journeys without regular braking or deceleration, the battery is not recharged. The electric motor is therefore rarely, if ever, in operation depending on the model and is an extra weight that leads to a slight overconsumption.
• Since 2017, it has not been eligible for the ecological bonus, unlike an electric vehicle.

To discover and compare all the models of electric and hybrid cars, do not hesitate to use our online tool.