Does petrol and diesel quality really vary between fuel stations in Australia? The short answer is that all major brands must meet the same national standards, so base quality is very similar; the main differences come from additives, marketing and which fuel is right for your vehicle.
Do fuel brands really differ?
In Australia, all petrol and diesel sold at service stations must comply with the Fuel Quality Standards Act 2000 and related regulations, which set limits for things like sulphur content, octane/cetane, aromatics and contamination. From 15 December 2025, every grade of petrol must also meet a maximum sulphur content of 10ppm, aligning Australian petrol with cleaner international standards and lifting the baseline quality across all brands.
Most of the fuel sold in Australia comes from a small number of refineries and import terminals, so the base petrol or diesel delivered to different brands is very similar before additives are blended in. Independent testing and motoring groups have found that while there can be small variations within the allowed limits, no major fuel brand consistently delivers “better” base fuel than others, and contamination events remain rare.
Where does Australia’s fuel come from?
Most of the fuel in Australia, whether it’s petrol or diesel, comes from the same base source. This means that the raw fuel you get at different stations initially starts out very similar. Australia’s fuel comes from a mix of domestic crude oil and significant imports, with over 70% of refined products coming from overseas, primarily Asia (Singapore, South Korea, Japan, Malaysia) for both crude and finished fuels. Some crude is sourced from the Middle East and Africa.
Once this base fuel is distributed to different fuel companies…
They add their own special mix of additives. These additives are meant to improve the fuel in various ways, such as helping to clean your engine or improve performance. Some additives might actually help your car run better, while others might not make much difference at all.
Fuel companies spend a lot on marketing to convince you that their fuel is the best. They use catchy slogans and slick advertisements to make their brand stand out. This marketing can make us believe that one brand of fuel is significantly better than another.
However, because of strict regulations, the basic quality of fuel remains largely the same across different brands. The real differences are often more about perception than performance.
So, while the base fuel you get is pretty consistent in quality, the additives and marketing can create the impression that some fuels are superior to others (but it’s not always the case!).
How petrol quality works (RON and what to use)
Petrol quality for most drivers comes down to its octane rating, measured as Research Octane Number (RON), which reflects how well the fuel resists knocking or pinging under load. Knocking happens when fuel ignites unevenly in the engine, reducing performance and, over time, potentially causing damage, which is why using the right RON for your engine matters more than the logo on the bowser.
In 2026, Australian petrol grades are typically:
- 91 RON (regular unleaded): Suitable for many everyday cars and usually the cheapest option.
- 95 RON (premium unleaded): A mid-grade fuel for engines that specify or benefit from higher octane.
- 98 RON (super premium): High-octane fuel designed for high-compression or performance engines that require or recommend it.
Your owner’s manual will specify the minimum RON your engine needs, and that should guide your choice. If your car is designed for 91 RON, using 95 or 98 will rarely deliver enough performance or fuel economy improvement to offset the higher price, while using 91 in a vehicle that requires 95 or 98 can cause knocking, reduced performance and potential long-term damage or warranty issues.
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Diesel quality explained (including renewable and synthetic)
Like petrol, diesel sold in Australia has to meet a national standard that sets limits for sulphur, cetane and other properties. Modern automotive diesel is low‑sulphur (10ppm), which helps protect emissions systems and reduces harmful exhaust pollutants.
There are a few diesel “types” you might hear about:
- Automotive diesel: The standard diesel you see at most stations for cars, 4x4s, trucks and buses.
- Renewable diesel: Produced from renewable feedstocks like vegetable oils or waste fats and refined to behave like conventional diesel, often with lower lifecycle emissions.
- Synthetic diesel: Made from natural gas, coal or biomass using processes like Fischer–Tropsch, formulated to mimic or improve on conventional diesel’s combustion behaviour.
For most drivers filling up at a servo, you’re simply choosing between regular and “premium” diesel, both of which must meet the same core quality standard. Premium diesel generally shares the same cetane rating but includes a heavier additive package aimed at injector cleaning, corrosion protection and foaming control. Independent testing and motoring groups suggest these additives can help keep modern high‑pressure systems cleaner over very long periods, but the day‑to‑day performance difference for a typical commuter is usually subtle at best.
Because premium diesel costs more per litre, many owners of everyday utes and SUVs are comfortable sticking with regular diesel, especially if they maintain their vehicles properly and use quality filters. Premium diesel can make more sense if your manufacturer recommends it, you have a sensitive modern diesel with known injector issues, or you’ve noticed clearer benefits in your own driving.
Truck diesel vs regular diesel
On the forecourt, “truck diesel” is less about what’s in the fuel and more about how it’s delivered. High‑flow truck diesel pumps are designed to fill big tanks quickly, not to work neatly with a small hatchback or SUV.
There are three practical differences you’ll notice:
- Nozzle size: Truck diesel nozzles are larger and may not fit into the filler neck of some passenger vehicles.
- Flow rate: The fuel comes out much faster, which is great when you’re pouring hundreds of litres into a prime mover, but can be hard to control in a 60L car tank and increases the risk of splash‑back or spills.
- Pricing and additives: Truck diesel is often slightly cheaper and tends to carry less “premium” marketing spin, but the underlying product still has to meet the same diesel standard.
If you’re driving a regular car or light SUV, it’s safer and easier to stick with standard diesel pumps. You’re not missing out on some secret “stronger” fuel by skipping the truck lane; you’re mainly avoiding oversize hardware and a much faster flow rate that wasn’t designed with smaller tanks in mind.
Premium fuels, additives and whether they’re worth it
Most major Australian brands offer premium petrol and diesel lines, such as BP Ultimate, Shell V‑Power, Caltex/Ampol Vortex and similar products. These fuels are built on the same base petrol or diesel as the regular grades but contain higher levels of detergents and other additives, and they’re heavily marketed around performance and engine cleanliness.
Common additive claims include:
- Engine cleaning: Detergents that help reduce deposit build‑up on injectors and valves over time.
- Improved combustion: Additives designed to promote more complete, stable combustion and smoother running.
- Corrosion protection: Inhibitors aimed at protecting metal surfaces and fuel system components from rust and wear.
There is some technical basis for these claims, especially in modern engines with fine‑tolerance injectors, but independent motoring groups point out that benefits are often modest and hard to measure in everyday driving. For most people, the smartest approach is:
- Follow the manufacturer’s minimum RON or diesel spec.
- Consider premium fuels for high‑performance or very new engines, or if you’ve personally noticed a genuine improvement in smoothness or economy.
- Don’t feel pressured by marketing into paying for premium at every fill if your car doesn’t need it and you haven’t noticed a difference.
The bottom line
For most drivers in Australia, there’s no magical “best” fuel brand – all major petrol and diesel must meet the same national standards, so base quality is very similar wherever you fill up. The smartest move is to use the fuel type and minimum octane your manufacturer recommends, treat premium fuels and additives as optional (not essential) extras, and choose stations based on price, convenience, and how well they’re maintained rather than marketing claims.
Save on fuel with a fuel card
If you’re looking to save on fuel, one of the most effective ways is to use a fuel card that matches how and where you drive. Use our fuel card finder to quickly compare options and find a fuel card that fits your vehicles, preferred stations, and monthly spend, so you’re not leaving easy discounts and rewards on the table.
FAQs
What is the best quality petrol type in Australia?
The best quality petrol type in Australia is usually 98 RON (Super Premium Unleaded Petrol). It has the highest octane rating, which can help your car perform better and run more efficiently. However, if your car doesn’t specifically need 98 RON, sticking with the recommended type (like 91 or 95 RON) is usually the best choice.
Does premium diesel offer any performance advantages over regular diesel?
Premium diesel has additives that may help keep your engine cleaner, but for everyday driving, the performance benefits are usually small – or in some cases, non-existent. Unless your vehicle specifically requires premium diesel or you notice a big difference in how your car runs, regular diesel is typically just fine and will save you money.
Is it better for my car to use premium petrol even if it’s not recommended?
If you’re using higher octane petrol, like 98 RON, in a car that only needs 91 RON, you’re just spending extra money unnecessarily. Higher octane petrol can offer slight performance and fuel efficiency improvements in vehicles designed for it, but any small savings in fuel costs will be outweighed by the higher price per litre. It’s best to use the petrol type recommended by your car’s manufacturer. So, if your car requires 95 RON, stick with that.
Is fuel from some brands better for my car than others?
While there may be slight variation to fuel between brands, no brand consistently stands out as better. Australia has national fuel standards that apply to all service stations, ensuring a basic level of quality. Issues like fuel contamination are very rare.
Is it okay to use a lower octane petrol than the one recommended for my car?
No! Using lower octane petrol than recommended can damage your engine and void your warranty. The RON (Research Octane Number) indicates how well the fuel can resist knocking. If you use 91 RON petrol in a car that requires 98 RON, you might hear knocking or pinging sounds, which is the fuel detonating uncontrollably. Saving money with lower octane petrol now can lead to expensive repairs later.
Do some fuels really clean engines as claimed by fuel companies?
There’s no independent research to back up the claims that certain fuels can clean engines. These claims are largely promotional and not verified by third-party studies.
Why are fuel prices higher in the country than in the city?
Fuel prices are often higher in regional areas due to the cost of transporting fuel over long distances. Additionally, there’s usually less competition in the country, so prices don’t need to be kept as low. Regional stations also sell less fuel than city one..
What happens if I accidentally put the wrong fuel in my car?
If you put 95 RON or 98 RON petrol in a car that only needs 91 RON, it won’t harm the car but will cost you more. However, using lower octane petrol than recommended can damage the engine over time. The worst mistake is putting petrol in a diesel car, which can cause severe engine damage if driven. If this happens, don’t start the engine—call for roadside assistance to have the fuel tank drained. Different types of fuel and inconsistent pump labelling mean you should always double-check before filling up.
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