Mild hybrid vehicles – also known as 48-volt hybrids or MHEVs (mild hybrid electric vehicles) – have an electric motor that assists the combustion engine. The electric motor kicks in when a lot of fuel is being burned, particularly during startup. It can also serve to boost the engine's power during acceleration.
The battery is exclusively charged via regenerative braking, which captures the energy created by the friction of braking, converts it to electricity and stores it in the battery. Mild hybrids do not use charging stations.
The main advantage of a mild hybrid is its fuel consumption, that is 0.1 gallons (per 62 miles) lower than that of a petrol car. Since less fuel is consumed, the vehicle can go farther on a full tank of petrol or diesel. Because the main propulsion system is powered by a combustion engine, mild hybrids benefit from the ubiquity of petrol stations. So mild hybrids are ideal for motorists who are looking for maximum range combined with low fuel consumption and who don’t want to worry about charging the battery.
Because they consume less fuel, mild hybrids have lower emissions, but the electric motor is not capable of powering the car on its own. This is why mild hybrids get none of the incentives that are offered for EVs and why they receive only two points for sustainability in our comparison of electric vehicles.