Petrol myths busted: what Victorian drivers should know about fuel, E10 and petrol prices

E10 fuel is regular unleaded petrol blended with about 9 to 10 per cent ethanol. It is often one of the cheaper petrol options at service stations, but some drivers worry it may cause problems for their car.

Whether you can use E10 fuel depends entirely on the year, make, and model of your vehicle. While most modern petrol cars built after 2000 are compatible, older models or high-performance vehicles can suffer engine damage.

Before filling up with E10, check the inside of your fuel filler flap, your owner’s manual or the manufacturer’s website. If your vehicle requires a higher-octane fuel, use the minimum fuel grade recommended by the manufacturer.

Because ethanol has lower energy content than petrol, E10 may lead to a slight reduction in fuel economy in some vehicles. Whether it is the cheaper option overall can depend on the pump price difference and how your vehicle performs on E10.

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Running close to empty occasionally is unlikely to immediately ruin a modern engine, but it is not a good habit. Keeping some fuel in the tank reduces the risk of being stranded and may help reduce strain on the fuel system, particularly if a vehicle is repeatedly driven with very low fuel.

If a vehicle is continually low on fuel, condensation may form inside the fuel tank. If water droplets build up, water could enter the fuel system and potentially damage components such as the fuel pump and fuel injectors.

Most modern vehicles also have a fuel pump located in the fuel tank, where fuel helps keep the pump cool. If the fuel level is too low for extended periods, the pump may be more likely to overheat and fail.

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Regional petrol prices are generally more stable and often higher than prices in the five largest cities, but they are not always higher, according to the ACCC.

Regional fuel retailers generally sell less fuel than metropolitan retailers, while transporting fuel long distances into regional areas can add cost.

However, regional prices can fall below Melbourne prices on occasion, particularly when metropolitan prices are near the peak of a price cycle. Regional drivers coming to Melbourne should check current city prices to see whether it is cheaper to fill up at home.

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The old “cheap Tuesday” rule no longer reflects how petrol prices behave in Victoria. While fuel prices still rise and fall, motorists can no longer rely on a typical pattern or fixed cheapest day. Global oil market volatility and Victoria’s new daily fuel price cap are changing how prices move, making it more useful to compare prices before filling up than to wait for an assumed low point.

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Petrol stations can sometimes sell below wholesale prices to match or beat competitors. Drivers who shop around can put pressure on retailers that want to keep customers. The ACCC describes petrol price cycles as periods where prices generally fall steadily before rising sharply again, which is why very low prices may only last for a short time.

The retail price may also be lower than the relevant wholesale benchmark for a period because of timing differences in the fuel supply chain, including the delay between fuel leaving the terminal gate and being sold at the pump.

Older manual cars often had a fuel-economy advantage, but that is no longer a safe assumption. Many modern automatics can match or outperform comparable manuals thanks to advances in transmission design, additional gear ratios and more efficient shift programming. Always compare the official fuel-consumption figures for the specific vehicle model.

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