Fuel for thought: which one should you choose?

Roll into a service station and you might find multiple grades of unleaded petrol, petrol-ethanol blends and even different diesels fighting for attention

So how do you know which nozzle to grab?

Here’s what you need to know

Man filling car up with fuel 


If you fill up on petrol, you have a choice of ‘regular’ 91 unleaded and two grades of ‘premium’, 95 and 98. So what should you be running? Simple – what your car asks for.

“Have a look at your manufacturer’s handbook or near the fuel cap – they’re your first points of reference,” says Viva Energy’s Retail Fuels Marketing Manager Gisella Spedicato. “They’re going to tell you what your car can and can’t take.”

These numbers - 91, 95 and 98 - refer to a petrol’s octane rating, or RON, which is essentially a grading of the fuel and its combustion efficiency.

A way of remembering this is like the Olympics – 91 is bronze, 95 is silver and 98 is gold. Generally, the higher the number the better the fuel. But because manufacturers optimise their engine tuning for a specific RON, it’s important to fill your car with the right one.

“Most cars can run on 91,” says Gisella. “But a lot of high-performance vehicles, sports cars and European cars nowadays recommend 95 or above.”

So, is that the end of the story? Not quite. While running a lower RON fuel than recommended can be bad news for your engine, there are other reasons to choose costlier premium fuels.

“The higher the RON, the higher the quality of ingredients in the fuel,” says Gisella. “If you really love your car and are willing to spend a little more to get a higher-quality product, or you rely on your car for your living, premium fuel will help you look after it.”

“With Shell V-Power 98, for example, you’re getting a boosted fuel that’s cleaner for the engine than Shell Unleaded 95 or 91. It’s designed to protect your engine by cleaning out the gunk and helping to ensure there’s none of that build-up, helping it run smoother.”

If your budget is tight, even an occasional fill with a premium fuel can be worth it. “If you can’t put 95 or Shell V-Power 98 in every time you fill up, do it every third or fourth fill and it will help to flush through the gunk and keep the engine healthier,” says Gisella.

Ethanol blends

Petrol drivers can also choose a petrol-ethanol blend, most commonly E10 (up to 10 per cent ethanol). This can be a good choice if you’re more price or environmentally conscious, so long as your car can take it – again, check your manufacturer’s handbook.

“A lot of people choose E10 because it’s a little cheaper than 91, they consider it a greener fuel or because it slightly reduces our dependence on foreign oil supplies and supports local agriculture,” says Gisella. “If your car can run on it, it’s a good choice because it has a higher octane rating than 91 – at 94.”


If you have a diesel vehicle, your choices are limited to two grades – standard and premium – and all diesel vehicles can run on the former. But, as with petrol, there are benefits to balance out the extra cost of a higher-quality blend at the pump.

“If you’ve bought the latest BMW diesel SUV or have a ute you earn a living from, the manufacturer’s handbook is not going to tell you to use premium diesel,” says Gisella. “But like premium petrols, our Shell V-Power Diesel is a boosted quality product that will help to prevent gunk building up in your engine and keep it healthy.”

Visit the Shell Australia Fuel Finder to find out what fuel are available at your nearest Shell fuel outlet.

To receive more great content from Shell directly to your inbox, sign up here.



Viva Energy Australia Pty Ltd (“Viva Energy”) has compiled the above article for your general information and to use as a general reference. Whilst all reasonable care has been taken by Viva Energy in compiling this article, Viva Energy does not warrant or represent that the information in the article is free from errors or omissions or is suitable for your intended use.

Shell Logo

Content originally produced by Viva Energy, Shell's exclusive licensee in Australia.