RAA MEMBER AND SUBSCRIBER NEWSLETTER 2 July 2026

[turboplanner]

7 hours ago, T510 said:

How does an oil become "not suitable anymore" when it was suitable from 1989 when the 912 series was released.

Refer to the small print. You as a user might think all those engines were identical. I was doing some research on the V6 Holden a while back and the one model has had multiple changes, some supplier, some material, some different machining etc. Mostly to improve the engine. It wouldn't surprise me at all if the latest iteration of the 912 has the same charts. In this process not every change gets the results that initial testing indicated. So the manufacturer issues Advice notice from a break point.

7 hours ago, T510 said:

 

Obviously different 912 models and derivatives may require different oil grades but if you have been using brand "x" oil for 20 years with no issues it begs the question how it becomes no longer suitable and why is a change required.

The oil company may have issued an update in the formula which affects the older engine. I would normally phone the service department if I wanted to contravene the Manufacturer Advice.

7 hours ago, T510 said:

 

A change in the SportPlus4 formula (if there was one, I don't know) doesn't make previously suitable oils no longer perform at the level required.

You wouldn't think so when it was supplying so many 912s, however we're talking about one phone call here; not the end of the earth.

 

Just a matter of interest; if the manufacturer has your details linked to tghe engine, you would normally get information relating to your engine direct based on the oil manufacturer discussions with the engine manufacturer.They usually get their heads together first on the degree of the problem, and what the owner needs to do, then decide who is going to communicate.

[Blueadventures]

4 hours ago, FlyBoy1960 said:

perhaps they have a different standard in Japan because they don't have the sport plus oil available in that market ?

On 8th April 2015 the second generation blend of the Sport Plus 4 oil was advised; likely due to market requirements and / or engine needs to better reaching the TBO in good order.

[skippydiesel]

21 minutes ago, Blueadventures said:

On 8th April 2015 the second generation blend of the Sport Plus 4 oil was advised; likely due to market requirements and / or engine needs to better reaching the TBO in good order.

Where do you get this from;

 

Read & Understand FlyBoy 1960 excellent history of Rotax Oil & AeroShell Sport Plus 4.(ASSP4)

 

• If an oil meets or exceeds the manufactures specification, it does not matter who makes it, what its called or the colour if the container it comes in.
• Sure we all have our favorite (trusted) brands - thats fine as long as the above is met.
• Rotax were happy to advise the specifications their engine owners should go for. As there was no alternative (AeroShell or similar product back then) thats what owners did and it all worked out just fine, as long as the owner/operator was burning ULP or not more than (if memory serves) 30% AvGas.
• Those wishing to use 100% AvGas or in excess of the 30% presented a problem, as the motorcycle oils,  that met the Rotax specification, were not formulated to deal with the high lead contamination delivered by AvGas.
• The main, not only problem, with AvGas & Rotax 9's is  the build up of lead in the gearbox - hense the 600 hr inspection  of the same (1000 hrs for ULP).
• ASSP4 first became available, in large part to address the needs of owners wishing to us AvGas  (I suspect mostly N American) It may be a coincidences but I feel it was about the time that that Rotax started to suggest that not using their OM products may lead to engine failure/shortened service life (scare tactics). The published oil specs. no longer appeared, replaced by ASSP4
• For the most part, owners who were happy with the motorcycle oil kept using it to good effect (cant remeber but likly cheaper than ASSP4) and some with particularly long lived engines are still doing so.
• Much of this went on when a Rotax engine TBO was 600 hrs, with incremental increases over 20 years to 2000 hrs - an unlikly progression if the wrong oil was being used by the fleet.
• Rotax engines routinely exceed TBO, without costly life extending interventions, in part because owners adhered to the earlier (motorcycle) oil specification advise and have continued to do so, with the advent of ASSP4 (and the no longer published oil specifications).
• I do not recomend using other than ASSP4, however I do believe that someone who is able to find the earlier Rotax oil spec and match it to a current motorcycle oil, could do so, as long as AvGas is not a significant part of the fuel used.

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