Understanding the Different Fuel Types in Australia

The options for fuel at the petrol station can be overwhelming if you need help understanding what each one offers. This guide aims to demystify the different types of fuel available, helping drivers and car owners make informed decisions the next time they are fueling up their cars.

What is RON?

The first place we will start off with is RON numbers. You may be asking, how does this have anything to do with fuel? Well, the numbers associated with fuel types, such as 91, 95, and 98, refer to the Research Octane Number (RON). The RON indicates the fuel's ability to resist pre-ignition or 'knocking'. Higher RON fuels can withstand greater compression before igniting, making them a better choice for your engine (hence the price difference at the petrol station).

Petrol Types

91 RON (Regular Unleaded)

91 is the most common type of petrol and is suitable for most engines. This fuel type is best for standard vehicles without high-performance engines and the benefits are that 91 is widely available in addition to usually the cheapest option.

95 RON (Premium Unleaded)

95 is a higher-octane fuel that offers better engine performance and efficiency. Usually, this fuel type is best for European vehicles and cars that specify 95 RON or higher. This fuel type Improves fuel economy and reduces engine knocking.

98 RON (Super Premium Unleaded)

98, also referred to as Super Premium Unleaded is the highest-octane petrol available at most service stations. This premium fuel is most suitable for performance vehicles and cars requiring high-octane fuel.

Ethanol Blends

E10 

E10 is a blend of 90% petrol and 10% ethanol, which is how it got its name. This fuel type is good to use on most vehicles built after 2000. The only benefit of E10 is that it reduces reliance on fossil fuels and is usually cheaper than pure petrol. However, it may result in slightly higher fuel consumption due to lower energy content.

E85

Similar to E10, E85 is a combination of two types including 85% ethanol and 15% premium unleaded petrol (RON 105).

This fuel type is best for specialised vehicles like the Holden Series II Commodore and selected SAAB and Chrysler models.

E85 is commonly used in racing (e.g., V8 Supercars) and is known to lower fossil fuel consumption significantly. However, using E85 in non-compatible vehicles can cause severe engine damage.

Diesel

Lastly, is the fuel type Diesel known as the lean-burn, which is commonly used in utes, commercial vehicles, 4WDs and some passenger cars. Diesel can only be used in vehicles with diesel engines so avoid using this fuel type if your car only takes petrol unless you want to destroy your engine. One of the major benefits of Diesel is that it offers better fuel efficiency and torque, making it ideal for long-distance driving and heavy loads.

Choosing the Right Fuel

To ensure you're using the best fuel for your vehicle:

• Check the Manufacturer’s Recommendation: Always refer to your vehicle’s owner manual for the recommended fuel type.
• Look for Labels: Some vehicles have labels on the fuel cap indicating the suitable RON.
• Consider Efficiency: While higher RON fuels can provide better performance, balance this against the cost at the pump.
• Be Cautious with Ethanol: Only use ethanol blends like E10 or E85 if your vehicle is compatible, as using the wrong fuel can cause significant damage. 

Choosing the right fuel is important if you want your vehicle to last a while. If you are unsure if your vehicle can take E10, the NSW government has an online resource you can use to check E10 compatibility.