With much of the world’s news talking about the impacts of emissions and pollution on the environment, the term ‘hybrid’ has become a well-known motoring buzz word especially as we look for ways to reduce. Most motorists know ‘hybrid’ is something to do with electric assist vehicles and often followed by words like Plug-in (Mitsubishi Outlander) and self-charging (Toyota Prius).
But there’s a new emerging technology called Mild Hybrid Electric Vehicle (MHEV), which is set to become a popular option in the race for a change to electric; especially as we see manufacturers slowing production of sole internal combustion engine (ICE).
What is a hybrid?
Seen as a bridge between a full electric and a combustion engine, hybrids are designed to lower overall fuel economy by using both an electric motor and a fuel combustion engine to propel the vehicle. They can either work together or independently. It essentially runs electrically on its own charge for short periods of time with the combustion engine switched off. This is why you see Toyota Prius vehicles crawling slowly away from the traffic lights trying to stay in ‘EV’ mode for as long as possible before the petrol engine is fired into life. A small battery is charged via the engine alternator and through regenerative braking.
Mild vs Hybrid
The key difference between a hybrid and a mild hybrid is that while a traditional hybrid’s electric motor is able to propel the car on its own, a mild hybrid can’t.
Mild hybrids are classified as fuel-electric vehicles, but it is the extent of how much the vehicle uses the electric motor that defines it as mild. The combustion engine in a mild hybrid is still doing all the heavy lifting with the electric motor serving only to assist.
In New Zealand this system is currently available in the luxury European segment, but over time we will see other manufacturers’ introduce their versions.
Mercedes-Benz uses a term called EQ Boost in the new CLS 450. This features a 48-volt integrated starter generator/motor alongside a combustion engine; and offers a better acceleration performance, lower emissions and improved efficiency. The EQ Boost system acts as both a starter motor and a “hybrid assist” motor. Though you do not plug-in to recharge the battery, the system recuperates energy from slowing down or braking for example.
Audi also use a similar system in the new Q8, where the 48-volt primary electrical system incorporates two important technology modules: a lithium-ion battery and a belt alternator starter. During braking, it can recover up to 12 kW of power and feed it back into the battery. The MHEV technology enables long coasting phases with the engine deactivated and a start-stop range that begins at 22km/h.
The benefits of such systems can include: Smooth engine start up, the battery charges with kinetic energy, short distances can be covered on electric power/ coasting, extra boost e.g. for overtaking, and reduced overall fuel consumption.
Not every mild-hybrid system is solely focused on fuel-efficiency, though. Ferrari’s flagship hypercar, the LaFerrari, is Ferrari’s first ever production car to be equipped with the Formula 1-derived hybrid solution – the HY-KERS system – which combines an electric motor with the most powerful incarnation yet of Ferrari’s classic V12 engine.
There is a downside to this technology: because mild-hybrid cars aren’t able to run on electric power alone, they are not as emissions- friendly as full EV types. Motorists after the ability to cruise through town on electric power alone must also look elsewhere, but this alternative system is another stepping stone into an EV future.