Everything You Wanted To Know About Petrol But Were Afraid To Ask

Everything you wanted to know about petrol but were afraid to ask

When it comes to filling the car up at a petrol station, most motorists know the basics - but there are some things that seem less straightforward.

By Shell on Sep. 01, 2021

To clear up any confusion at the petrol pump, here are the answers to a few popular fuel questions.

Q: Can I use a lower octane fuel than the one recommended for my car?

A: No, as it can produce things like loss of power or acceleration, loss of fuel economy, or a knocking or pinging sound in your engine.

Petrol is graded by a RON (Research Octane Number) rating, which is 91 (standard unleaded), 95 (mid-range premium unleaded), and 98 (high-range premium unleaded). Always refer to your manufacturers handbook as that will advise you on the recommended fuel type for your car. Failing that, you can also find this information inside the fuel flap of your car – it’ll tell you what octane you should be using for peak performance.

Q: Will premium fuel keep my engine cleaner?

A: Depending on the type of premium fuel chosen, absolutely. A premium unleaded fuel like Shell V-Power 98 has been infused with powerful cleaning agents that remove gunk (aka carbon deposits, if you want to use the technical term) from your fuel injectors and inlet valves, and it also protects against corrosion, which can lead to serious problems for your car’s innards. Even using Shell V-Power 98 every second or third fill will have a positive cleaning impact on your engine and help to keep it running more efficiently.

Q: Is there a fuel that assists your car to run more efficiently?

A: Premium fuel like Shell V-Power 98 contains friction-reducing molecules (who knew petrol could be so science-y?), derived from Friction Modification Technology (FMT), which is a fancy way to say it helps protect against wear and tear on critical parts of your engine.

This in turn helps your car run more efficiently, with the engine able to deliver more power to the wheels, thus making your driving experience a far more pleasurable one.

Q: Do any fuels create fewer emissions?

A: The good news is that studies show the higher the octane, the lower the emissions your vehicle produces.

This is backed up by the Australian Government’s Department of the Environment and Energy, which notes that vehicles using high-octane premium fuels are more efficient, therefore using less fuel and creating fewer greenhouse-gas emissions.

Q: What happens if I accidentally put the wrong fuel in my car?

A: If it’s recommended your car uses standard 91 unleaded petrol, it’s totally fine to upgrade to a premium 95 or 98 fuel - in fact, it’s going to be better for your vehicle, akin to treating it to a deluxe spa treatment.

Putting a lower octane fuel in your car is a no-no (see above), but fear not, as it won’t instantaneously kill your car.

It will, however, put your car’s combustion cycle out of whack, resulting in the aforementioned knocking/pinging sound, as well as affecting the car’s fuel efficiency. Don’t worry, there are a couple of solutions: adding a bottle of octane booster to your car, and/or a fuel flusher (both are readily available at auto stores) will help.


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.

Where information, recommendations, opinions or ideas have been sourced from third parties external to Viva Energy (Third Party Information), Viva Energy cannot be certain that the Third Party Information is accurate, current or complete, nor should a mention of any business, product, service or website of a third party be taken as a recommendation, approval or endorsement of, or warranty or claim regarding, that business, product, service or website.