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Hybrid Cars: What Are They and How They Work?

24 June 2019 AutoMarket, Tips & Advice

Since its introduction 20 years ago, hybrid cars have come a long way from just being considered as science projects to one of today’s significant automotive innovations. Buyers from around the world have enjoyed the efficient and eco-friendly services of hybrid cars. They’ve become so popular that almost all manufacturers in the market, from high-end to humble cars to commercial vehicles, have adopted the hybrid powertrains.

Research by JP Morgan even suggests that by 2025, hybrid cars are going to take over 30% of all vehicles sold. That’s equivalent to 8.4 million cars for an almost 8% market share.

Here in Australia, Toyota dominates the hybrid segment selling 1,458 hybrid vehicles, 9.6% of its total sales for the month of April.

With its rising popularity, hybrid cars are becoming an interesting subject among motorists, dealers and even first-time car buyers. To satisfy your curiosity, here’s what you need-to-know about hybrid cars.

What are hybrid cars?

By definition, hybrid cars are a combination of two elements: an electric motor and a traditional gasoline engine. These two systems work with each other to power the drive wheels. In a hybrid car, electric motor sometimes does all the work, sometimes it’s the gas engine but oftentimes, they work together. Less gasoline is burned, better fuel economy and electric power boosts car’s performance in certain instances.

Hybrid cars have a high voltage on board battery pack that can be located in the trunk behind the rear seats or in the floor pan for improved handling. This on board battery provides the juice for the hybrid’s electric motor.

The Toyota Prius started the hybrid trend in 1997 upon its introduction in Japan followed by the Honda Insight, launched in 1999 in the United States and Japan. It slowly found its niche in the auto market through the years with its main selling point being reduced fuel consumption. After all, the fuel economy is the main reason why hybrid cars were invented.

How does the engine and motors work together?

It may sound complicated and out of the ordinary to have both the engine and electric motor wrapped under the same hood of a car. Amazingly, it works just as fine and efficiently too. Here’s how a hybrid works with two different systems:

During normal cruising, only the gasoline engine is used. By using the gasoline engine, it powers the generator, which in turn produces electricity and stores it in the batteries to be used later. 

When pulling away from a stop, the electric motor draws power from the battery to power the car. Up to 15 MPH, the vehicle uses only the electric motor for power. This is one of the main reasons why hybrids are more efficient to drive in the city than on the highway.

During heavy acceleration, both the gasoline engines and the electric motor work together to power the wheels. The power-split transmission makes it possible for the engine and motor to work together by combining the torque that each one puts out. During acceleration, the generator is powered by the engine while the motor uses electricity from the battery and the generator as needed.

When reaching a complete stop, both the engine and the motor are turned off. The power from the battery is utilised to run all the auxiliary vehicle systems such as air conditioning system, radio, and lights.

What’s under the hood of a hybrid car?

A hybrid car is consist of the following parts:

  • Gasoline engine – most cars have a gasoline engine, however, a hybrid car’s engine is smaller in size and is packed with advanced technology for fuel efficiency and reduced emissions.
  • Electric motor – the electric motor also uses advanced technology to run the car and to generate power as well.
  • Fuel tank – this serves as the energy storage device for the gasoline engine.
  • Generator – the generator produces electrical power.
  • Batteries – are energy storage devices for the electric motor. The electric motor can put energy into the batteries as well as draw energy from them.
  • Transmission – A hybrid’s car transmission performs the same function as the conventional car’s transmission.

What are the different types of hybrid cars?

Parallel Hybrid

The common transmission that blends the two power sources of the electric motor and gasoline engine are connected in a parallel hybrid design. Those transmissions can be an automatic, a manual, or a continuously variable transmission (CVT). Examples are the Toyota Prius and Chevrolet Volt that uses power –split continuously variable transmission (CVT) that is a very popular hybrid transmission among car enthusiasts. Parallel hybrid cars determine the acceleration, sound and feel by the transmission type and the size of the gasoline engine that the car has. Toyota, Ford, Kia, Honda, Lexus, Hyundai, Lincoln, Infiniti, and Nissan are some car brands that uses the parallel design.

Series Hybrid

There is no physical mechanical connection between the engine and the wheels in a series hybrid design. The electric motor provides the thrust and the gasoline engine is there to recharge the battery. The driving experience is more of a smoother, powerful acceleration with less vibration when the gasoline engine engages. An example of a series hybrid is a BMW i3 (with range extender).

The BMW i3 with the range extender is an example of a series hybrid.

Plug-In Hybrid

Another enhancement to the conventional hybrid concept is a plug-in hybrid car. It has a much larger battery pack that must be fully charged using an external electricity source (home, office or public charging station).  The greater amount of energy storage can significantly reduce fuel consumption by allowing extended all-electric driving (between 15-55 miles) depending on the car’s model. If you recharge it every day, you’ll be running on electricity most of the time.  If the car depletes the all-electric range, it automatically reverts to being a conventional parallel hybrid.

Mild Hybrids

All of the above are considered "full hybrids," which means that the electric motor is capable of moving the car by itself, even if it's for a short distance. In a "mild" hybrid, it cannot. Just as in a full hybrid, a mild hybrid's electric motor is there to assist the gasoline engine for the purposes of improving fuel economy, increasing performance, or both. It also serves as the starter for the automatic start-stop system, which shuts down the engine when the car comes to rest in order to save fuel. Originally envisioned as a simpler and cheaper means of bringing hybrid technology to market, mild hybrids don't improve fuel economy to the extent that full hybrid systems can. As such, they never enjoyed the same popularity. Recently, however, mild hybrid powertrains are making a comeback, as evidenced by the adoption of 48-volt electrical subsystems in vehicles such as the Ram 1500, Mercedes-Benz E-class, and Audi A6, A7, and A8. Basically, car companies are now applying mild-hybrid technology to just about every new model.

Hybrids will likely become more popular in the coming years with automakers pushing towards car electrification. If you’re looking on to save money on fuel, a hybrid car may just be a perfect choice. Be sure to select the right car for your budget and driving style. Since it’s not your conventional car, it’s good to have an idea first of how to use it before deciding to buy. 

Ready to discover what a hybrid car has to offer? Visit us at to find a car that’s best for you.