Hybrid Electric Vehicle

What is a hybrid electric vehicle ?

A hybrid vehicle is equipped with both a combustion engine and at least one electric engine.

The different engines can be computer controlled and can work in combination (in series or in parallel) or independently. Depending on the technology used, the engines are mobilized differently during the vehicle's driving phases: starting, acceleration, braking, etc.

To store and supply the electricity needed to power the electric engine, a hybrid car also has batteries.

The specificities of a hybrid electric vehicle

Depending on the level of hybridization implemented on the vehicles, there are now 3 main families of hybrid electric cars:

  • Mild Hybrid Electric Vehicle (MHEV): equipped with a starter-alternator, they recover the vehicle's braking energy stored in a battery. The battery is then used to manage the Start & Stop system in the city or to power an electric engine that relieves the combustion engine to save fuel. We also talk about micro-hybrid cars ;
  • Full hybrids or full-hybrids, known as HEVs (Hybrid Electric Vehicles): unlike mild-hybrid vehicles, these cars run on 100% electric power when they start up and up to a speed of about 50 km/h. Beyond that, the combustion engine takes over ;
  • Plug-in Hybrid Electric Vehicle (PHEV): equipped with a more powerful electric engine and more robust batteries, this system allows for 100% electric driving for a distance of 50 to 60 km, before the internal combustion engine takes over. The batteries can be recharged from the mains.

Light hybrids () are easier to produce than full-hybrids () and plug-in hybrids (). They are therefore less expensive to purchase. But the savings are much less on light hybrids.

Examples and practical application

The interest of hybrid vehicles is to be able to save fuel and limit the CO2 emissions of the vehicle by recovering the deceleration energy of the vehicles to reduce the operation of the thermal engine.

The savings that can be achieved with a hybrid car are of the order of:

  • 10% to 15% for mild-hybrids or micro-hybrids, provided they are used in cities ;
  • 15 to 20% for full-hybrids on mixed routes (city and expressways), or even 40% in urban traffic ;
  • at least 20% for plug-in hybrids in mixed traffic, not counting the range given by the recharged batteries.

Plug-in hybrids also make it possible to use electricity generated by renewable energies, such as solar power, advantageously.


Hybrid electric vehicles in numbers

For the first time in France, hybrid car sales surpassed diesel sales in May 2021. With 36,221 registrations, they represented 26% of new car sales, compared to 22% for diesel vehicles.

Of the 32,088 new cars acquired in the fleet in January 2022 (non-auto company, government and non-short-term rental cars), hybrid car registrations outpaced gasoline engines, at 29% vs. 28%. Plug-in hybrids () dominate (12%), followed by full-hybrids () at 10%, and micro-hybrids () at 7%.

Regulatory framework

Regulations related to hybrid electric cars focus on safety issues related to electrical hazards, battery and reporting of these quiet cars.

  • Regulation No. 100 of the Economic Commission for Europe of the United Nations (UN/ECE) - Uniform provisions concerning the approval of battery-operated electric vehicles with regard to specific construction, functional safety and hydrogen emissions.