Driving a fuel efficient car is becoming more important than ever and not just because of what you are paying in petrol or diesel to run your car. With global climate change and non-renewable resource concerns, car manufacturers are constantly improving their vehicles with the aim of reducing their fuel efficiency.
Figuring out what is going on within a car technically can help you make better choices when it comes to saving money in ongoing costs, as well as potentially reducing your carbon emissions.
There are many factors which contribute to your car’s fuel efficiency, so read ahead to break down the language of cars, and get a better understanding of what contributes to a car’s fuel consumption.
Fuel Economy Figures
A car’s fuel efficiency is how much fuel your car is using to run, and fuel economy ratings tell you how much fuel your car uses in litres per 100kms. The lower these ratings the less fuel you are using to run your car.
These fuel consumption figures are an excellent way to compare between different vehicles. However they should be viewed as a guide only as driving style and vehicle, weather, road and traffic conditions are likely to affect the fuel economy you achieve.
Engine Size Matters
When talking about fuel efficiency and power, you will note the size of the engine will be specified with a number followed by the word “litre.” For example, a 1.5L engine.
Engine size determines the total volume of fuel and air that is pushed through a car’s cylinders. This volume is measured in cubic centimetres (cc) which then, thanks to the ease of the metric system, can be easily rounded up to the nearest tenth of a litre. For example, a 1598cc engine is translated as a 1.6L engine.
Small Engines [1.0L – 1.9L]
Small engines are considered more economical as there is less space for fuel and air inside the engine to power the car. However, due to the smaller capacity they also tend to have lower power outputs which means they may not provide the performance levels at higher speeds compared to larger capacity engines. If you are using your car to drive shorter distances such as getting to and from work, and zipping around town then a smaller engine is going to be more fuel efficient.
Large Engines [2.0L +]
Large engines are more powerful but are usually designed to pump higher volumes of fuel and air through its cylinders to achieve this power. The result tends to be faster acceleration and higher top speeds but higher fuel consumption too. At open road cruising speeds a bigger engine is not having to work as hard to propel your car along so the fuel consumption in this situation can be closer to a small capacity engine.
Lighter Cars Cost Less
When you are browsing at your local dealership or on their website, take a look at the specifications sheet and see what the car weighs. Generally, as physics would suggest, less fuel is needed to move a smaller and lighter car and more fuel is needed to move a larger and heavier car.
Aerodynamics & Body Shapes
An aerodynamic body shape can be a surprising factor in fuel efficiency. Less drag on the car means the vehicle is able to move with less effort, meaning less fuel has to be used.
The more upright or taller stance of a vehicle the more the drag increases, while a smoother raindrop design has less amount of drag.
When considering a fuel efficient vehicle, it’s a good idea to consider the body shape. Here are some of the more common ones:
- Sedan - A vehicle that sits close to the ground with a lower center of gravity. Sedans tend to perform better around corners and sharp turns than larger vehicles such as SUVs.
- Hatchback – A smaller vehicle than an SUV. The main difference between a hatchback and a sedan is the luggage area can go to the roof, providing extra space for cargo.
- SUV or Sports Utility Vehicle - A larger vehicle with a higher center of gravity, higher ground clearance, and oftenfour-wheel drive. With an SUV, you’ll have a more commanding view of the road.
- Crossover - A cross between a hatchback and an SUV. A crossover give you the best of both worlds with a higher seating position and can be available with all-wheel drive option.
- MPV or People Movers – More like a small van, an MPV is generally taller and longer than an SUV offering spacious 3 row seating for 7 or more passengers.
- Utes - Big, rugged vehicles designed to perform big, rugged tasks. Tall, wide and long, you’ll have a bird’s eye view of the road.
If you are interested, you can see how aerodynamic testing contributes to the design of Suzuki vehicles here.
An Electric Twist: The Hybrid
If fuel efficiency and lessening your carbon footprint is something that you are passionate about, then looking into an electric or hybrid (a combination of petrol and electric) vehicle is a must.
The hybrid vehicle uses a combination of electricity stored in batteries and petrol in a fuel tank to get you to your destination with considerably less fuel consumption.
The most common hybrid electric vehicles have 3 different ways in which the car wheels can be powered:
- Powered solely by the petrol or diesel engine with the batteries powering all vehicle electrical systems
- Powered solely by the electric motor with a small capacity petrol or diesel engine used to charge the batteries
- Powered by a combination of the combustion engine and the electric motor
Unlike a purely electric car, a hybrid doesn’t need to be charged via plugging the car in (unless the car is specified that it is a plug in hybrid or PHEV).
More effectively, the battery self-charges through a process called regenerative braking. When a regular petrol/diesel car slows down through braking, the energy of the car is dispelled from the vehicle in the form of heat. However, in a hybrid, the electric motor is activated during the process of braking and is able to save the energy and divert this power into the batteries to be used for later.
Hybrids are fuel efficient in the following ways:
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Engine auto-stop. When the car is running but not in motion (idling), the engine is automatically turned off reducing fuel consumption and emissions. Electricity then restarts the car smoothly and silently.
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Low level speeds. Depending on the model, hybrids use the electric motor to assist or completely run the car at low level speeds, meaning very little fuel is used until the petrol engine later takes over as speeds increase.
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Powering electrical systems. When cruising the battery helps power all of the additional electrical systems and components such as lights, radio, and air conditioning.
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Aerodynamic design. As the point of the hybrid is to be as fuel efficient as possible, there is greater emaphasis on smoother edges and lightweight materials to reduce air drag. Some models include drag-reducing tyres to assist fuel efficiency.
The Full Electric
On the most fuel efficient end of the scale, an electric car uses only electricity stored in batteries to move you from A to B.
With no CO2 emissions, electric cars do not have a fuel rating. However, they do require you to plug it in and take electricity from the national grid.
When considering fuel efficiency, ensure you do your research as the price and features can vary vastly.
Your local dealership can explain the fuel economy rating and fuel saving features of the cars you are looking at and are more than happy to assist you with any questions you may have.
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