CHOICE membership

Synthetic Engine Oils


I wish you well if you ever have a warranty claim without a dealer service history, you’re in an excellent position to advise them on what should happen. Do let us know how it goes, particularly if it’s a major repair on a prestige vehicle and the dealer obliges with minimal resistance. This is now a synth oil thread so I won’t be posting further here on this.


It is not always that simple! If the dealer is obliging great.

If you need to start quoting the ACCC and consumer law the system is far from fixed. More so if it becomes emails and a paper trail.

Hopefully the system is improving and we can all now phone Ford or Toyota direct and get them to respond when the dealer is not fair dinkum?

It is Interesting that the USA has a long established industry practice of encouraging customers into 3,000mile (approx 5,000km), 3 monthly service intervals. That is despite owner manuals recommending much longer intervals.

Is this reflective of Australia?
Are service providers recommending service intervals more often than the owners manual?
Is the average Australian car owner changing oils every 5,000km?

At least here in Australia typical services are 6 or 12 monthly, and at 10,000 to 15,000 km intervals.

It is also of interest that these longer oil change service intervals have been common in Australia for some time.

The Ford 6cylinder BA series have a 15,000km 12month service interval, since 2002. The recommended oil for this service interval is a SJ/CF grade oil 10W30.

Castrol recommend their Edge 5W30 A3/B4 engine oil
And Mobil, their Mobile 1 5W30 engine oil
Both are synthetic based products good for 12 months or 15,000km.

Would the same oils go further in the same vehicle and still perform to specification?
Of course they would.
The service interval is set to ensure they do not fail early, given a wide variation between users.
After 15,000km how much further could you go or how much longer would they last?
There is no one single answer. It might be 2,000km. It might be another 15,000km.
The variability is a statistical reality, given the many different factors involved.

Can the result for a Ford BA 6 cylinder be transposed directly to mileage with the same oil used in a VW Golf tsi110?
No, because the two engines are significantly different in design.
Just a very simple fact.

In practice with engine oil, or an air filter or any other wearing part of a vehicle, do you want to replace it after it has failed, not knowing for how long it has been past it’s use by date, or before when it is still in serviceable condition?

If it was a million dollar gearbox on a ten million dollar machine, when would the oil be replaced? Before the lubricant has failed, or after it has failed to perform to specification?


I know a surprising number of people who religiously patronise auto dealers service, appliance manufacturers showrooms, and so on, and don’t pay attention to the premium prices or The Good Guys sales nor do they trust independent garages or service companies. Manufacturer or nothing for them. There are clearly enough of them to keep the dealers shops working since they remain in business.


My experience with engine oil replacement is worthy of note. I had my 2 year old vehicle serviced by the main agent, which of course included oil replacement (synthetic). I have little trust in vehicle service agents, manufacturer appointed or otherwise, so immediately on returning home, I pulled the dipstick, initially to check the level. The oil on the dipstick was dark brown and very obviously had not been replaced. I rang the RACQ and asked for information on having an oil sample tested. When they learned the reason, they became unwilling to supply any information. I then rang around oil testing laboratories and essentially received the same brush off. When they found out why I wanted the oil tested, they found some very cute reasons for not offering any service. The industry clearly wishes to protect its reputation.
Having worked in the mining industry, where the engine oil in heavy duty haul trucks is replaced according to its condition and not hours run or distance covered, I am well aware that engine oil can not be left in the engine indefinitely. Engine oil gradually becomes contaminated by water, combustion products, wear products and its acidity increases. Leaving old oil in an engine is an invitation to rapid wear and eventually engine failure. Modern synthetic oils do a great job in dealing with these contaminants but still need replacement at the appropriate interval.


But the question remains: “What is the appropriate Interval”. This is where the motoring industry is letting everyone down. It seems their focus is the service industry rather the actual lubrication need. Hopefully Choice will investigate Synthetics with your insight involved ie, oil sample testing based on a) lengthening time periods and b) lengthening mileage.


Perhaps a more appropriate and direct resolution might be to arrange testing of your vehicles oil directly. I can’t recommend a particular service provider, however there are a number of options evident from a simple web search.

Some options that pop up include:



As there is some scepticism evident in the discussions so far, it is worth noting that the major lubricant suppliers also offer oil laboratory testing services. There is often a debate as to whether they can be relied upon. Fortunately when tied to million dollar fuel and lube contracts they are unlikely to risk providing poor service or unreliable advice, given the consequences of getting it wrong!

Translating best practice from the mining industry to everyday private use motor vehicles is an interesting comparison.

Perhaps, given the mining industry also uses and needs to maintain large fleets of service vehicles (road registered or registrable 4WD utes and wagons from Toyota, Nissan etc) it might be worth asking how often they service or change engine oil?

That only takes account of one of the many recommended servicing and inspection requirements.


This is a Consumer Association, rather self help group, ie, what is needed is for Choice with all independent resources to investigate.


Isn’t the Choice Community also about sharing information and ideas, including suggestions that assist others with consumer issues?

The Canadian broadcaster CBC has been producing a consumer orientated investigative program and recently looked at concerns around oil change intervals for newer vehicles. They wrapped up with an oil sample test, and asked the expert from the independent lab just how much longer the oil might be good for. The answer is in the YouTube clip.

Are you asking the following question?

Scotty also has this to say about claims oils might last a long time.

The reference to the fine print attached to the Mobil1 promotion says it all.

Even Mobil USA with all the hype of an oil change at up to every 20,000 miles, adds ‘or 12 months’ which ever comes first.

Mobil did run a Chevy Silverado for 500,000 miles changing the engine oil every 20,000 miles. They followed this up with a strip down.

Of course this was run simulating continuous highway driving. About as low stress as it could be and the big Chevy engine is designed for heavy duty truck work. A 5.3l V8 push rod technology design for those who might like to draw comparisons with a 1.3l Honda Jazz.

There is also a trial run with a Toyota Camry, notable also as a great and long lasting Taxi in Australia.

There is a choice community section specifically for requesting tests.

I agree there may be a general consumer issue concerning over servicing with particular providers.

Whether there is any benefit in Choice going further to recommend extended service intervals any greater than the OEM manuals, I remain very guarded and dubious that specific recommendations can be made without attached liability?

None of these tests come close to replicating everyday motoring usage, if ever it could be defined?


The examples you provide are fantastic. But Australians and particularly Australian media are unlikely to do everything people like you have done here, and I before initiating this thread, ie, searched the web, etc. Hence, we need our Consumer Association to do what the Canadian Market Place etc has done, to highlight the issue nationally, and hence lead to change.

That is my driver here rather than only self help, ie trying to activate Choice, that requires more than just one member, me, putting up a suggestion on the Choice web site.

By the way, and thanks to you for the link, I think many of the initiatives Canadian Market Place have done and the way they have generated interest is great to see, it is better version of the ABC consumer programme ‘Checkout’ that I think was done with the support of Choice


There can be no defined “appropriate interval” since this is very largely dependent on the vehicle usage. What is appropriate for a taxi, running many hours a day, is totally inappropriate for a vehicle used only to go to church on Sundays. The appropriate interval is found by engine oil analysis, which can be performed on a small sample of engine oil extracted via the dipstick tube. What is required is for such an analytical instrument to be present in all service centres, and for the consuming public to have confidence in the integrity of the service agent using it, perhaps enforced by a printout of the results of the analysis. This would undoubtedly result in most vehicles having greatly extended oil change intervals, not too popular with service agents who make a killing on their selling price of lubricants.


If one chose to test oneself independently (or even through a dealer where costs are passed on to the consumer) , I imagine the cost would be compatible to the cost of an oil change. Which should one do…change the oil and save the cost of the test? Or pay for a test to confirm quality and then cost of the oil change?

Environmentally testing makes sense to reduce waste, but it would be a hit on the consumer’s pocket and potentially seen as counterproductive (financially) in the long run.

I can see equipment with significant engine oil volumes (e.g heavy equipment), the cost may pay off as changing oil early would be a significant cost.


If it could be a simple card test like checking the PH of your soil, then the cost would be negligible.

However, at present, with synthetic oils, it seems that the difference for all types of users is possibly a vast difference. Orders of magnitude different to the 5000k or 3 months. Those who are preaching that every user is different seem to conveniently be ignoring that it applies to all oil types and users today, ie, they are using the 5000km or 3mths, when that may not be suitable for everyone either. The point is that for most having a interval guideline is better than nothing, but that guide also needs to be relevant, and it seems that it is not for synthetic oils. That is where consumer groups can make a difference NOW, not after some easy test has been innovated.


Unfortunately it isn’t. …see the first video from @mark_m above.

It also appears that visual inpection of an oil does not indicate its condition either.

Thinking further, it is likely that the optimum duration betwwen oil changes would chamge over the life of an engine and also engine working conditions.

For example, on new, I suspect the oil would need an eariler regular change to remove metal contaminants and residues from its manufacture. As a motor ages, it potentially could have more exhaust/burnt fuel and oil contaminants caused through engine wear. Such may mean more regular changes.

Likewise I suspect a vehicle which idles a lot (sitting in traffic for considerable time each day) and does 10000km per year would need more regular oil changes than a car that does the same distance and doesn’t sit in traffic.

Likewise for towing or a car fully loaded (with passengers, especially a big family), compared to a single occupant vehicles.

There are numerous variables which would affect optimum frequency and maybe manufacturer recommended durations is based on a more worst case scenario than an optimistic one. One duration is unlike to be optimum for all.


Everything you say, isn’t synthetic specific, it applies to every engine. Yet, the current regime has been used for decades without question. Only now with synthetic oils which are clearly very much more advanced, has there been a need to re-appraise.

I feel you are just trying to kill the conversation, and in so doing letting the current regime be retained even though it clearly inappropriate for Synthetics.

As to the testing, you reference is to the limitation of today;s science and technology, not tomorrows innovation, to which I referred.


Synthetic oils are part of the consideration. It may be obvious. It may not be.

Many current vehicle manufacturers lubricant recommendations can only be easily met with synthetic base formula engine oils. Hence the recommended service intervals take synthetic grades into account.

Synthetic oil only describes the base oil blend, which compared to a straight refined oil blend Is easier to produce within defined performance parameters. The final product is a combination of the base oil properties and additive packaging. The additive package is complex and essential in achieving specification of any engine oil. Both are critical to meeting specification.

A synthetic base engine oil with a cheap additive package may be worse for an engine than a high quality refined mineral oil blend with a quality additive package.

It is complex, and there is plenty of evidence to demonstrate the outcomes. The VW group which includes Audi and Bugatti brands at one end through to Skoda has a unique range of requirements. These recognise variations in engine technology, application and vehicle use. A third party assessment presented as simply as I have seen follows.

For VW which has developed it’s own specifications for engine lubricants this assessment demonstrates to me it is really a question the manufacturer is most able to answer. Synthetic base engine lubricants are part of the VW DNA!

Notably VWs extended service intervals come with a requirement for a smart trip meter that derates the life of it’s high spec synthetic oil requirements according to vehicle usage!

Perhaps the real need being asked for is not about synthetic engine oils? Should consumers be asking for a smarter engine monitoring package and trip meter that assesses the service life of the lubricant?

This does not however remove the need for other inspection and service requirements that reasonably need to be performed on a calendar time basis?


This thread is about Synthetic Oils!!!

Who cares what the manufacturers say! The evidence is they don’t care about the customer only the retailers and service industry. That is precisely why we need Choice to stand up and do their role for consumers.


No, just fleshing out all the variables…for discussion and consideration.

There are multiple factors which affect the changing and potential use of different oils, including synthetic oils.

It could slso be reasonable to assume that if there was a difference between synthetic and traditional engine oils, one or the other may be better at different times in an engines life and/or through how the vehicle/engine operates.


Yes, it is such a complex topic. Balance is always difficult. With this topic in particular there is Tribology, the science of lubrication, a field in which there are dedicated Engineers and Industrial Chemists. The design and development of internal combustion engines involves another broad team of technical professionals with intimate knowledge of lubrication needs.

@longinthetooth has introduced the competitive interests of the manufacturers and markets and asked if consumers are being abused by the industry. There is one particular very technical question in mind here on the life of engines oils used in passenger vehicles.

It may be useful to consider one more variable. ‘Oils ain’t Oils’ is an old cliche.

Reality is that synthetic base oil used in an engine is not a single product. It is typically a recipe blended to produce different outcomes for each product, grade and specification.

Mobil 1 products which are full synthetic engine oils previously mentioned are promoted as lasting longer than their competitors products, and offering superior protection.

However customers can buy an engine oil from numerous other brands, to the same ASTM specification without the same assurance. ASTM specifications are test requirements. They are not chemical formula for the product. Different suppliers/brands do have different formula for competing products. Some are identical, and simply rebranded, or very similar with variations in the additive package.

Hence it is impossible to determine one universal answer to how long an engine oil might last simply because it says synthetic. No two synthetic oils are assured of being the same base oil.

Just because a base oil is produced by synthesis, provides no assurance it is any better a product. It is simply modified or different. The result depends on the actual chemical structure selected for the oil or blended oils in the final product.

IE A trial of one branded product that uses a synthetic base oil is used in a particular long mileage test is not evidence that any or all synthetic motor oils are equally capable? Other brands might do better, while some may fail! Which to choose then?

The specialist lubricant suppliers will each have us believe their particular product has magical and superior properties, to prove the point. Even that may be open to a Royal Commission if the truth is to be found. :roll_eyes:

The secret is in the additive packages, not quite as closely guarded as the KFC secret recipe or Coke’s famous formula.

The challenge is perhaps not much different in appearance than a Choice test of Black and Gold vs Coles brand vs Uncle Toby’s. Just don’t invite me for the taste test, and consider not all tastes or dietary needs are the same! Happy to assist if I get to drive the spectrometer. Although they are so automated these days. :wink:


It is somewhat reminiscent of what the oil companies used to try to do in advertising their leaded fuels decades ago.

They would variously claim that their fuel provided more power, better economy, kept your engine cleaner, increased engine life. etc, etc.

You could even “get a tiger in your tank”.


Great adds and what a nice tiger!
Certainly more appealing than a car being chased down the highway by a transformer like monster of black goop and scrap metal, escaped only by pulling into a servo of brand X.

Keeping to the topic oil changes came around far too often back then. No synthetics needed, however better engine design made a big difference in seeing service intervals increased.

While there were no synthetics, BP, Castrol and others all had a range of high performance motor oils, all very capable without the use of synthetics. Something to do with being highly selective with the source of the refinery feed stock required to produce the lubricant base oil/s and matched additive packages. In certain instances some of the additives were left out. Less additive, more lubricant! Castrol R, BP Coarse or Coarse+.

One source/brand suggests modern engine lubricants can be up to 10% additive, 90% base oil.