For the next two months, the petrol flowing into Australian cars may be slightly different. Here are the effects of dirty fuel on your car.
What’s happening?
Energy Minister Chris Bowen announced on yesterday that it will temporarily allow higher sulfur levels in petrol for 60 days in an effort to boost fuel supply and stabilise prices. The change is designed to unlock roughly 100 million litres of additional petrol per month that would otherwise be exported.
The government says the move is primarily about supply security, particularly for regional communities.
The fuel itself won’t look different at the pump. But chemically, it will be slightly “dirtier” than what Australian fuel standards normally allow.
Higher sulfur limits mean refineries and suppliers can blend fuel that normally wouldn’t meet Australia’s standard. According to the announcement, this will free up petrol that would otherwise have been exported and redirect it to the domestic market.
Ampol Australia has already committed to prioritising this redirected supply to areas facing shortages and to the wholesale spot market used by independent distributors.
The policy comes amid disruptions in global oil markets tied to the war in the Middle East. The International Energy Agency (IEA) has encouraged member countries to release fuel supplies in a coordinated effort to calm markets.
Australia is considering its own contribution as part of that international response.
The government says the temporary rule change will help relieve pressure on fuel distribution chains without affecting overall consumption.
What ‘dirtier fuel’ actually means
First things first: so-called ‘dirty’ fuel doesn’t mean it’s literally full of dirt and refuse. The key change here is the fuel’s sulfur content.
It might shock you to learn but oil is actually full of stuff you don’t want in your car at all, let alone exploding in your car at speed.
Sulfur, for example, occurs naturally in crude oil. During refining, most of it is removed. That;s because sulfur creates pollution and interferes with modern vehicle emissions systems.
Modern engines are therefore designed to run on low-sulfur fuel, which is why governments tightly regulate it.
Again, Allowing more sulfur doesn’t mean the fuel contains dirt or debris. It means its chemical composition is slightly less refined.
What it means for your car
For most drivers, the short-term impact will likely be negligible.
Let’s look at it from an average driver’s perspective. In Australia’s best-selling vehicle, the Ford Ranger ute, which has an 80-litre fuel tank and roughly an 800km range, Australians drive about 265km a week. Over the 60 days the dirtier fuel will be available, that works out to roughly 2,270km of driving, meaning the average driver would go through just under three tanks of fuel.
The prevailing wisdom suggests that this isn’t great for your car, but it isn’t catastrophic.
Modern vehicles are built with multiple layers of protection against variations in fuel quality. Engine computers constantly monitor combustion and adjust ignition timing, while filters and sensors help shield sensitive components.
Drivers may notice:
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slightly reduced fuel efficiency
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marginally higher emissions
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minor changes in engine performance under heavy load
Degradation due to fuel quality typically occurs over long periods and large distances, rather than a few weeks of driving.
What happens if we have to do this again?
Obviously, the conflict in Iran isn’t over. Just today we heard from its new leader that it won’t be giving up the fight any time soon. Ships are on fire in the Strait of Hormuz and the missiles and drones keep flying day and night.
This is set to continue to choke oil supply for the world, meaning Australia might have to do this sort of thing all over again.
Over time, the biggest risk to your vehicle from higher sulfer fuels that are less refined is the physical contamination factor. While not these things don’t explicitly make a fuel ‘dirtier’, they’re still definitely there.
Water, sediment, or microbial growth in fuel can damage injectors and high-pressure pumps because modern fuel systems operate at extremely high pressures and microscopic tolerances.
Those types of problems usually stem from storage or distribution issues, not fuel quality regulations.
In those cases, the first component to fail is usually the fuel filter. That’s a good thing, because it’s meant to fail after catching nasties that would otherwise end up in your engine. Still, replacing it isn’t ideal.
Here’s to the next 60 days at the pumps!
