Toyota’s hybrid technology has been offering drivers unrivaled comfort and refinement, low running costs and improved fuel economy since 1997. But how many people know how it actually works?
In this post we aim to explain clearly and without technical jargon precisely what Toyota’s Hybrid Synergy Drive is, how it works, and how it benefits the environment and your wallet.
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What is a hybrid?
Vehicles are described as ‘hybrids’ if they contain two or more power sources. Within the road-car sector, most hybrid cars feature an internal combustion engine and an electric motor, but the way these interact with one another means there are three different kinds of hybrid setups.
Toyota has pioneered what is called the ‘full’ hybrid system, which uses two separate powerplants – battery-powered electric motor and petrol-driven combustion engine. Each of these can power the car alone, or in combination. This is the world’s most popular hybrid system and has sold well over five million units since it was first launched in Japan in August 1997.
The second kind of hybrid is described as ‘parallel’. This uses a combustion engine as the primary source of power, directly assisted by an electric motor that is fitted between the engine block and gearbox. This set-up tends to offer less functionality than a ‘full’ hybrid system. The challenge of fitting the electric motor into a very small space limits the power and range of the EV set-up.
Finally, the third kind of hybrid is the ‘series’ type. This type of vehicle is driven by an electric motor; the combustion engine has no direct connection to the transmission, so it is only there to generate electricity to power the electric motor. The challenge for ‘series’ hybrids is maintaining efficiency once the battery is depleted. Cars with ‘series’ type set-ups are rare.
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How does Hybrid Synergy Drive work?
Hybrid Synergy Drive comprises six primary components: petrol engine, electric motor, electric generator, battery, power control unit, and a power split device that uses a special planetary gearbox to distribute power from the engine, motor and generator.
Viewed as an overall, Hybrid Synergy Drive is a smart, fuel-saving technology that is used to switch seamlessly and automatically between the electric motor and the petrol engine.
Adapting to driving conditions, it intelligently manages the flow of power from both sources and also tells the car when to combine the two for maximum efficiency and on-road performance.
As the name suggests, the system delivers real synergy between the two power sources. When the petrol engine is running, it charges the battery via the generator; and when conditions allow it, such as in slow-moving traffic, the generator cuts out the petrol engine and lets the electric motor take over for zero emissions travelling. The sophisticated engine management system also recognises when the car is stationary and switches off to conserve power and cut emissions, automatically switching back on again when needed.
Plenty of charge is supplied to the battery, so a car with Hybrid Synergy Drive will never need to be plugged into a mains supply for recharging.
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How are the batteries charged?
As well as using the energy from the engine to charge the battery, Toyota’s Hybrid Synergy Drive charges its battery through regenerative braking, a system which makes use of braking energy.
Each time the brake pedal is pressed or the driver comes off the accelerator to lose momentum, controllers divert energy back to the battery for recycling. In other words, the braking energy that would otherwise be lost as heat and noise, or simply wasted altogether, is captured and used to power the electric motor later on. In continuous stop/start traffic, a great deal of energy is recaptured and stored this way, contributing to the overall efficiency of the car.
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How long do hybrid batteries last?
Toyota’s hybrid batteries are efficient, corrosion-resistant units designed to last as long as the vehicles they power. So confident is Toyota of this fact that each hybrid battery is given an eight-year/100,000-mile warranty.
The batteries are substantial units, required to generate and sustain sufficient voltage to power the car in low-speed situations, without any support from the petrol engine. Their production does have a small, additional impact on the environment, but this is more than compensated for by the environmental benefits of driving a hybrid car.
Procedures have also been put in place so that each battery can be recycled, arranged through Toyota dealerships.
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Is the engine different to that of a normal car?
Yes, it is. Unlike conventional four-stroke engines, the internal combustion engine used in vehicles with Toyota Hybrid Synergy Drive uses a slightly different cycle that produces less heat and also reintroduces cooled exhaust gases into the combustion chambers to further reduce engine temperatures.
Engines with traditional cycles sometimes need to use more fuel than necessary in order to reduce temperatures in the combustion chamber and stop the catalytic converters from overheating. This does help to preserve components but it also uses more fuel. Toyota’s solution, however, is more fuel-efficient and has proved to be phenomenally reliable.
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Do I have to drive differently to make the most of hybrid technology?
Absolutely not. Toyota Hybrid Synergy Drive is fully automatic and will optimise the use of precious fossil fuel for each driver. All you have to do is enjoy the road ahead!
For a further explanation of Toyota’s hybrid technology and how it works, why not watch this special ‘Mythbusting’ video by actor and technology presenter Robert Llewellyn.
VIDEO Hybrid Mythbusters: Toyota Prius - Carpool Special