Have you ever stood at the petrol station, parked car waiting behind you, and wondered just which fuel you should be filling it with? You have a plethora of regular options, but chances are you’ve also spotted the more enticing ‘premium’ petrol or diesel choices. If you’re not one to get complacent with your car’s health then you have probably chosen premium more than a few times, but what exactly does it mean for your car?

Whilst there is much debate as to which cars actually need premium fuel – many suggest that using your manufacturer’s suggested quality will do – a brief look at one of the main supplier’s product pages will give you an idea of you what to expect. One major fuel supplier, for example, says of its premium fuel range…

(It) is our most advanced petrol with a minimum octane of 98 and a formulation designed to bust the dirt in your engine to restore and maximise performance.

Cutting through the marketing jargon, it’s clear that one of the main things being sold is the fuel’s engine maintenance qualities. This is one of the major advantages present in both premium diesel and petrol and is thanks to detergent additives that are present in the formula. They essentially clean the engine by dislodging dirt that would otherwise remain charred to the insides. Interestingly enough, companies aren’t required to reveal exactly what is added to do this.

The next more obvious factor that makes these fuels premium is their Octane (petrol) and Cetane (diesel) levels. This is the number that is more often than not in the fuel’s title and can range anywhere from 89 to 100.

Whilst both Cetane and Octane operate in different ways, higher levels of either allows most engines to use the fuel more efficiently and thus create more power for fuel used. However, to what extent these premium fuels actually improve your car’s efficiency is contested.

Assuming your car is able to take advantage of higher octane fuels, NRMA has come up with a rule of thumb on just how much more you are getting out of your petrol car because of the increased Octane levels. Using 91 Octane fuel as the starter’s mark, a move up to 95 Octane petrol will see your engine consuming 4% less fuel. If you are feeling even more adventurous, filling your car with 98 Octane will see reduce your fuel consumption by roughly 7% when compared to 91 Octane.

The effect of a higher Cetane level in diesel fuels is less cut and dry. What is true is that it allows for the engine to run healthier – you’ll benefit from faster ignition, more power and less harmful emissions. To the delight of suppliers, who are beginning to single out its sale as key for driving profits, the popularity of premium fuels has been climbing quickly. This is powered in part by an increase in cars that demand it is a minimum, a realisation of its cleaner nature but also a convincing marketing campaign. According to statistics released by the Department of Industry, Innovation and Science premium unleaded petrol now makes up around 13% of fuel sales. However, if you limit the sales to just New South Wales that number climbs to 18%.  That’s nearly one in five cars being filled with a premium fuel.

Whilst it is hard to deny that marketing has been a large factor behind the success of premium fuels, it is incorrect to just pass them by as a marketing stunt. Long term, continuous use of premium petrol and diesel will allow your car to run healthier. Just make sure you consult your manufacturer’s guide before using it, there you’ll find if your car can take advantage of the benefits.

– Connor Pound