Motor Vehicle fuels - are the brands all the same?

@TonyIbrahim’s recent article on contaminated fuel might be of interest to commentators on this thread.

An engineer’s view on that:


Fabulous video, very interesting and humorous as well…! I learnt a bit, and got a laugh too! Thanks for posting! :slight_smile:

1 Like

@Fred Great video . Very informative

Good video @Fred.

The recent RACQ magazine (The Road Ahead) for Queensland members had an article on using high octane petrols. It debunked some of the myths and said that unless your car’s injection and computer system has been specifically designed for high octane fuel, there is no benefit in using it. A car engine’s specifically designed for high octane fuel will be outlined in the car’s operating manual.

A car not designed for high octane fuel will use the same amount of fuel as one mL of high octane fuel will have the same energy output as a lower octane fuel. There are also no additional benefits in relation to efficiency, engine power cleaning motor, less emissions etc for those vehicles not specifically designed for it.

The RACQ alluded that the ‘myths’ exist (and maybe perpetuated by) and allow the fuel companies to sell high octane fuel to unsuspecting buyers so that their margins are greater.

In summary, they said that the buying high octane fuel for cars not specifically designed for it is a waste of money (that being the marginal cost between high octane and lower octane fuels).

This is a link to the summary: RACQ Website


Thanks for that link. John Cadogan (AutoexpertTV) is brilliant. Expert and funny with it. I always enjoy and learn from his videos.

The other scam that we hear nothing about, of course, is that there’s a difference between brands, when we know it all comes from the same Asian refineries.

Bound to have been addressed previously, but in buying, let’s say either diesel or 91 octane unleaded at different marketers, is there any difference in what you get? Marketing goes into Premium and Special for those products, and without making price caparisons, because that is random, any difference in formulations or functions?

In Australia, the Australian fuel industry and fuel suppliers must meet legislative requirements:

The formulations (esp. additives) can change between manufacturers so long that the fuel sold meets the above requirements.

1 Like

Thanks. But with that being said, and we will assume everyone meets those minimum standards, are there some that are “better” than others? I would imagine that a lot of foodstuffs meet minimum standards, but some are “better” than others?

1 Like

The automobile associations have found there to be slight variations within and between fuel suppliers…with not one consistently better than the other. This is what one states…

There is marketing puffery which tries to sell a fuel as having some additive or slightly different characteristic to others, but, as found out by the AAs, this isn’t necessarily the case.

Notwithstanding this, the main differences to whether a fuel is better may be due to storage rather than brands. Fuel stored poorly which allows water intrusion or is stored for a long time will be worse than other which have no water/stored for short periods.


There are many anecdotal stories about this fuel and that fuel being better in this vehicle and that vehicle but I am unaware of any scientific comparisons showing a statistically significant difference between brands (and their premium additive packs they put in their fuels). Differences between 91-95-98 can be important so follow your manufacturers recommendation.

As for myself I buy Ampol most of the time only because I have a good discount program available (beyond Woolies) and I avoid Shell because they have a higher markup between 91 and 98 than Ampol, at least in my area.

That being written I have never had a problem with bad fuel although I know people who have gotten some with water, specific station dependent. As long as one buys from a station having a reasonable volume and avoids fuelling from a tank that is being or has just been topped up by a tanker they should be a much of a muchness. The topping up can cause sediment (if any) to rise from the bottom and potentially be sucked up and into your vehicle.

I admit to one foible. My car is specified for 95 but I use 98 because of direct injection and a hope the extra detergents I hope are in the 98 may keep it running better longer.


This is maybe a big question. After a product is made, and maybe any additives put in, it is stored, then transported, then stored again, then dispensed to consumers. But this happens with butter, cheese, olive oil, lots of other things.

Consumers really only care about the quality of the fuel they buy at the bowser, they should not care how it got there. So has there been a test of fuel properties across the board to confirm things like the real octane amount, or the (maybe slight) presence of water, or other effects of lengthy or improper storage. Just do it in a few capital cities and a few regional areas.

Vehicle fuel is a huge consumer cost, much more than butter or mattresses, so kind of important.

1 Like

Yes, testing is done by DCCEEW in conjunction with the National Measurement Institute. See:

I haven’t searched to see if they post results of testing they do. If they don’t post them, one might be able to obtain tests results by making a request… assuming the results can be released publicly.

Fuel companies are also likely to do their own bowser testing as well. Where they do, I suspect the results won’t be publicly available as it will be considered commercial in confidence.


A secondary confusion is who owns what and where do they get their fuel. Hint: Count our refineries and distribution storage facilities. Notice the branding on the delivery tankers? Often Toll Holdings.

While the first is a 2016 link little has changed excepting Caltex is now Ampol (the Caltex branding license - owned by Chevron - expired but same supplier/operator) and Chevron purchased Puma and will eventually rebrand Puma stations as Caltex.

A 6 year old anecdotal thread on Reddit.

Some personal perspective, in the early 1980s I worked for the Texaco (now owned by Chevron) Geophysical Center. Texaco fuel in the USA was always a few cents more than any of the competitors but many motorists swore by it as being better - it was 100% advertising and the reason for the higher price was higher costs from older and less efficient equipment.

Re the Reddit thread, regarding the ‘logo seen at race tracks’ it is related to sponsorship so long as the product meets the requirement. It would be difficult to assess if all the suppliers met the requirement but BP had a larger marketing budget to seal the deals.

Unless one has personal experiences they ‘swear by’ for their own vehicle or an experience with local stations that do have varied qualities of management and maintenance, it is usually the eye of the user.


Absolutely correct, and I have moved your question to this older topic which covers this exact question. The answers above will be of interest to you as well.

As you will have read, the only real difference is the addative(s), such as cleaners, that may be added.

When I had a diesel vehicle I used to buy my own additives from auto bits retailers and add it periodically as needed. It worked out significantly cheaper than paying 10-20c/L for the fuel from a garage that had added it in for me.

Since having pertrol cars which motor along nicely and don’t have any issues, I haven’t bothered, thereby saving 10-20c/L for every L of fuel.


The greater concern is Australia’s lesser standards for fuel compared to the rest of the world, notably for petrol.

It’s been a concession to the local industry, which produces only 24% of Australia’s refined product needs. The other 3/4 is imported.

Australia's dirty fuel – and when it'll get cleaner | CarExpert

Euro 6 emissions standards were introduced in Europe back in 2015, and call for no more than 10 ppm sulphur for all fuels.
There’s a deadline of July 1, 2027 for these standards to come into effect here. By then, even stricter Euro 7 regulations will have come into effect in Europe.
As a condition of the Australian Government’s fuel package, the two remaining refineries must complete their upgrades by 2024 and supply fuel with no more than 10 ppm sulphur.

Until 2027 Australia will remain a convenient market for higher sulphur petrol.


For so many categories, we seem to be the dumping ground for inferior products.


My original idea was trying to rate, in a few city and regional markets over a short period of time the qualities of diesel and 91 octane unleaded at various labelled vehicle fuel supply brands. It disregards marketing, how long stored, how transported, whether additives added or not, but a simple test of what comes out of the bowser, the ultimate consumer technical requirement. Did A have a higher octane level, or less grit, or less water content, than B, or C, or whatever. Tests would be done similar to, let’s say, the latest butter test, where people are really interested in how good the butter is, not if the cows listened to Chopin while being milked or not, for instance. Would take a few days in each city to capture samples, then analyse, then move on, a snapshot, yes, but worthwhile? Too many local dealer variables, as in the X branded here is not the same as the X branded over there? I certainly appreciate that it would be objective just over a short period, but some subjectivity would be taken out.

As you have mentioned, fuel is a big part of the family budget. It’s an admirable objective, if it does make a difference. One the various state level member motoring organisations have a core interest in. Would they be the best placed to respond?

They have a very large membership, mostly all motorists, strong relationships within their sector, and very significant funds. Far greater resources it may be suggested than Choice that has a very broad consumer base, and is 100% reliant on membership contributions.

Having raised in particular, how long stored, how transported, ….

Doesn’t the way a fuel is transported, handled and stored determine these outcomes, more so than any thing else?

Noted that prior posts have referenced in several instances fuel quality advice by several Aussie motoring organisations. What were their concerns?

It’s worth also noting that the motoring organisations point out that using a higher octane rating than required for a vehicle is of no benefit. Should one score a brand of 91 octane unleaded that tested 92 from the bowser at one servo any differently?

1 Like