Confused with the ever-changing landscape of hybrid acronyms? Just when you thought you understood the difference between a hybrid and a PHEV, along comes a mild-hybrid-plus and the impressively named super-hybrid.
As not all hybrids are equal – variations in the different systems impact fuel economy and C02 emissions – we’ve prepared a handy guide to break down the different options currently available in New Zealand.
HYBRID (or HEV)
HEV stands for Hybrid Electric Vehicle, otherwise known simply as a hybrid. Sometimes these are referred to as ‘full hybrids’ to avoid being confused with a mild hybrid (we will explain the difference shortly).
The EV part of HEV means there is a low voltage battery and small electric motor that works alongside the ICE (petrol) engine. There are no external plugs; the battery in a hybrid can self-charge via kinetic energy from deceleration or braking. This type of charging is commonly known as regenerative braking or charging.
You may have also heard the phrase ‘parallel hybrid system’. Parallel means both the petrol and electric motors can drive the wheels independently. Driving in electric-only mode won’t get you far –typically only one to two kilometres – but it all helps with emission savings.
The Toyota Prius was the first mass-produced hybrid vehicle, amassing over six million sales since 1997.
KEY POINT: Hybrids, or ‘full hybrids’ use both battery and petrol power to propel the vehicle.
Mild Hybrid (MHEV)
Originally known as ‘battery-assisted hybrid vehicles,’ the naming convention has evolved to a more consumer friendly moniker: mild hybrid, or MHEV.
The key difference between a hybrid and a mild hybrid is that while a traditional hybrid’s electric motor can propel the car on its own, a mild hybrid can’t.
Mild hybrids use the battery to ‘assist’ different functions like air conditioning and start/stop systems. On some vehicles the mild hybrid system can add power to the ICE engine, although the size of the battery would make any power gains minimal.
Mild hybrids utilise low voltage batteries, generally between 12 to 48 volts. By comparison, the battery in a full hybrid, like the Toyota Prius, is 201.6 volts. Mild hybrid batteries are self-charged in the same way as full hybrids, kinetically, through regenerative energy.
Emission savings for mild hybrids is considered low compared to full hybrids.
KEY POINT: Mild hybrids can provide moderate electric assistance but cannot be propelled by battery power alone.
Mild Hybrid Plus (MHEV Plus)
Coming to an Audi showroom near you soon, the German carmaker has added a new acronym to the Hybrid word salad, mild hybrid plus (MHEV Plus).
Audi call it a more sophisticated mild hybrid system that utilises a small battery (48 volts) that acts in a similar way to a large battery hybrid system.
Not only can the system boost ICE engine power (up to 18kW) it can also operate in full EV mode during moderate city driving, switching the petrol engine off, as well as propel the vehicle from a stop start.
Audi have added powertrain generator technology, recuperating energy using the mass of the entire vehicle which allows for faster energy regeneration than a standard hybrid system.
KEY POINT: Full HEV driving characteristics using a much smaller battery.
PLUG-IN HYBRID (PHEV)
Plug in Hybrid (PHEV) vehicles typically have larger batteries than hybrid and mild hybrid vehicles, giving drivers the ability to travel further in full EV mode.
For example, the Mitsubishi Outlander PHEV carries a 300-volt battery which allows for an EV range of over 80km.
PHEV vehicles can be charged kinetically through regenerative methods but can also be charged by plugging into a wall socket or public charger. To get the best fuel economy and lowest emissions, it is recommended to maximise the use of the battery by driving in EV mode as much as possible.
An added benefit of some PHEV vehicles is a feature called Vehicle to Load (V2L). This is known as a bidirectional power supply, or simply using the vehicle’s battery as a back-up power source to power appliances: think medical equipment, fridges, cooking appliances or lights. Suddenly, your vehicle becomes the camper’s best friend!
KEY POINT: PHEVs can drive further in EV mode than other hybrids and are charged predominantly by an external power source.
SUPER HYBRIDS
Super-Hybrid is an obscure science fiction film from 2011, as well as a new term coined by EV car company BYD. These vehicles operate in a similar way to traditional PHEVs (with a large battery that can power the vehicle in EV-only mode to ranges over 80km, working alongside an ICE engine).
Super hybrids can charge the battery three ways: by traditional plug-in or kinetic regeneration or by using the ICE engine as a generator to continuously top up the battery while the vehicle is operating in EV Mode.
This technology is known as a ‘range extender,’ meaning the petrol engine is only being used for assistance rather than as the primary mode of propulsion.
The stated range of super hybrids can be more than 1,000km, with excellent fuel economy and emissions profiles.
KEY POINT: Super hybrids use new range extender technology to maximise EV range.