Technologies

What is hybrid?

Hybrid cars usually combine a small capacity petrol engine with an electric motor to boost performance, reduce fuel consumption and emissions.

There are a number of variations in Hybrid technology:

A Series hybrid runs only on electricity and uses a small petrol or diesel engine as a generator to produce electrical energy to charge the batteries that power the electric motor.

This technology is expected to become available in Australia over the next few years.

A Parallel Hybrid has one or both motors generating drive. The electric motor is used to drive at slow speeds, for example, moving along in congested traffic, but after a certain speed threshold, the petrol engine kicks in and augments or takes over from the electric motor, and also recharges the batteries.

At present only parallel hybrid cars are available in Australia.

In the future, it is expected that the use of diesel engines will lower fuel consumption and emissions from hybrids even further.

What is an Electric car?

Electric cars run solely on the power of electricity stored in batteries and super capacitors, which drive one or more electric motors.

The motors can be installed in the wheels either at the front or rear of the car. This has the added benefit of lowering the centre of gravity and improving handling.

Electric cars still face challenges in terms of range between charges. The way you drive, the number of passengers, weight of luggage and whether you use ancillaries such as air conditioning can greatly affect the range.

Although electric cars have no direct emissions, the electricity used to recharge them certainly has emission implications, and until we de-carbonise the electricity grid we will not truly have emission-free motoring.

Another issue to be resolved is how quickly an electric car can be recharged. At present, most cars require an overnight charge for a complete top-up, but faster chargers are coming which can reduce this to minutes instead of hours.

What is a high-efficiency diesel engine?

Diesel engines are now capable of great efficiency and deliver low exhaust emissions. When compared to a petrol engine, diesel can use about 30 percent less fuel for similar performance, reducing consumption and thus emissions.

Most modern turbo-diesels are fitted with an exhaust particulate filter as well as a catalyst to ensure their emissions are cleaned up. The highest standard for passenger car emissions falls under the Euro 5 standard, which means what comes out of the tailpipe is far less noxious than previous emissions. Black smoke, for example, is completely absent in current vehicles.

High-pressure common rail fuel injection and variable geometry turbochargers coupled with very advanced computer control of the combustion process helps not only ensure high levels of engine efficiency, but also ensures the engine emissions are strictly controlled.

This makes modern diesel engines quiet, clean, powerful and frugal.

Diesel engines now power more than half of new cars sold in Europe.