How Do Hybrid Vehicles Work? 

Hybrid cars, often referred to as HEV for ‘hybrid electric vehicle’, combine a conventional internal combustion engine with an electric motor, both of which work together to power the vehicle’s drivetrain. 

The result is (theoretically) more efficient, improving fuel economy and reducing exhaust emissions. HEVs can sometimes also operate on fully electric mode over short distances, allowing for zero-emission commutes and dashes to the shops. 

A HEV usually doesn’t have a mains plug — if it does, it’s a plug-in hybrid or PHEV. Instead, the battery, in most cases is recharged from the combustion engine, as well as by recovering kinetic energy from the wheels during braking. 

So how does this help make the vehicle more efficient? 


How are HEVs More Efficient? 

HEVs are more efficient than internal combustion engines (ICEs) in many ways: 

Multiple Energy Sources 

By drawing power from the battery, the vehicle can accelerate more quickly without putting as much strain on the combustion engine. This allows you to reach faster speeds in a shorter time, without burning as much fuel.

Reduced Exhaust Emissions 

A direct consequence of the above is that, during periods of high acceleration, the combustion engine is not producing as many exhaust fumes. This allows HEVs to offer comparable performance to conventional ICEs, but with fewer emissions. 

Kinetic Energy Retrieval 

Kinetic energy recovery systems, or KERS, were developed for Formula 1 cars and later added to HEVs as a way to recharge the battery under braking. This means the combustion engine doesn’t need to burn as much fuel to charge the battery, again improving fuel economy and reducing emissions.


Types of Hybrid Electric Vehicle 

There are several types of hybrids, most of which contain ‘HEV’ in their acronym, along with another letter that tells you what type of hybrid the vehicle is. 

MHEV: Mild Hybrid Electric Vehicle 

MHEVs work as described above, with an electric battery that assists the combustion engine during acceleration, and which is recharged from the engine via kinetic energy retrieval. 

FHEV: Full Hybrid Electric Vehicle 

FHEVs are capable of driving in fully electric mode. Their range is typically much shorter than that of a battery-electric vehicle (BEV) that has no combustion engine, but for short city hops, they offer excellent fuel economy and minimal emissions. 

PHEV: Plug-in Hybrid Electric Vehicle 

PHEVs are probably the best-known four-letter acronym in the hybrid vehicle world. Unlike MHEVs and FHEVs, PHEVs come equipped with a mains electricity connector so that they can be charged directly from a power supply, with no fossil fuel needed at all. But they also have a fuel tank to allow them to run on petrol or diesel. 

Of the three, PHEVs are usually designed to operate over a longer range. As such, they can be used for medium-distance drives, and not just for commutes within the same town or city. 


Plug-in vs. Self-Charging Hybrids 

MHEVs and FHEVs are described as “self-charging hybrids” because they never need to be plugged into an electricity supply (and, in fact, they cannot be plugged into the mains as they have no charging port). 

In a sense, PHEVs are also self-charging, as the battery can recover energy from braking and the combustion engine, but to benefit most from their low emissions and better fuel economy, it is more sensible to charge the battery via a mains electricity supply. 


Is a Hybrid an Electric Car? 

The onboard battery makes all hybrid vehicles ‘electric cars’ as it is used to power the drivetrain, and not just the ancillary circuits like headlights, air conditioning and onboard sound systems that an ICE’s 12-volt battery is used for. 

However, there is also a big difference between any vehicle with a combustion engine and a fully-electric BEV — and sales of new HEVs are destined to be banned from 2035 as the UK works towards net-zero road transport as standard. 

Until then, hybrid cars can be seen as a compromise or as a ‘best of both’ solution. For example, during periods of high petrol prices, a PHEV can be charged from the mains, including overnight when tariff prices are often lower. 

In contrast, HEVs do not need to be plugged in for hours to refuel, as you can just top up your tank at a petrol station as normal — making them a good option for anyone who lives in an area where EV charging infrastructure is not yet commonplace. 


Do HEV Batteries Need Replacing? 

Like pure-electric cars, HEVs contain lithium-ion batteries, which store energy efficiently and in high quantities, making them the perfect candidate to deliver power to a vehicle’s drivetrain when it is needed. 

MHEVs have the smallest batteries, FHEVs are next, and PHEVs typically have the largest and heaviest batteries. 

On most modern HEVs, the battery is designed to outlast the car. This means on the top hybrid cars and hybrid models, there should never be any need to replace the battery, unless it becomes defective in some way. 

All batteries become somewhat less efficient over time, and HEVs are no exception. But with the pace at which electric vehicle technology is evolving, and the move towards net-zero vehicles by the mid-2030s, any older HEVs will likely be obsolete in other ways, before the hardware of their batteries wears out. 


Get Behind the Wheel of an HEV 

The best way to get to grips with HEVs is to drive one, and a leasing arrangement is a perfect opportunity to do that without committing to long-term ownership of an HEV.  

Whether you want to try out the technology, or you’re keen to get some real-world experience before potentially transitioning to a fully electric vehicle , leasing is the way to do it

If you’re a fan of a manual gearbox, HEVs are also the way to go, as their internal combustion engine is capable of supporting traditional manual transmission, while their battery will give you extra horsepower during acceleration. 

To find out more about the top hybrid cars and hybrid models on the market today, contact Synergy and get behind the wheel of the perfect HEV for your personal or business leasing needs.