RAA MEMBER AND SUBSCRIBER NEWSLETTER 2 July 2026

[facthunter]

Comparing spark Plug brand to a special oil has limited value.  Almost no relevance at all. The problem with the oil is you are asking it to perform often Opposing things because of the way the engine is designed. The friction required in  a clutch is inconsistent with  reducing it elsewhere and Lubing hot gears.  Any Power loss in a gear train results in Heat as does the (required) clutch friction. and there's long periods of no Let-up.  1 or 2 percent would be a two bar radiator output and that's way under what is Probably happening.. Nev

[Blueadventures]

On 03/07/2026 at 5:22 PM, T510 said:

I'm with Skip on this one. I don't think it is appropriate behavior from RAAus.

 

 Regarding oil standards, they are well established and have been around for over 100 years.

 

Rotax originally specified a high-quality 4-stroke motorcycle or aviation oil with an API classification of "SG" or higher because the engine features an integrated gearbox. They also stated gear additives are required, but no friction modifiers should be used. Plenty of Rotax's are around that have been running oil that meets that requirement without destroying themselves.

 

While SG is now obsolete, any modern API SP, SN, SM, SL, or SJ motor oil is a direct equivalent to the obsolete API SG rating. Current API classifications are fully backwards compatible with earlier classifications.

 

That was likely back at the period when the blend of the Sport Plus 4 was altered by shell, black bottles to the red bottle.  At the time it was strange that the sport plus 4 blend was changes and the branding retained.  Then the high quality motorcycle oils became inappropriate.

[BurnieM]

Sorry I went off at a tangent.

 

The point was that complying with  everything an aviation manufacturer says 100% may in some cirumstances be required but to do it blindly can also get you killed.

[skippydiesel]

2 hours ago, Blueadventures said:

That was likely back at the period when the blend of the Sport Plus 4 was altered by shell, black bottles to the red bottle.  At the time it was strange that the sport plus 4 blend was changes and the branding retained.  Then the high quality motorcycle oils became inappropriate.

I didn't want this Thread to be about oil, but if you cant beat the divergents, you might as well join in.

 

 

"......blend of Sport Plus 4 was altered by shell, black bottles to the red bottle."

 

Do you know for a fact ,that the Sport Plus 4 Black Bottle oil, was chemically any diffrent to what was in the Red bottle?

 

FYI: When talking oils its usual to use the term  formulation, blending is what they do with wine, whiskey, cake mixes etc.

 

What is "...inappropriate..." about using an oil, which meets/exceeds the specifications set by the manufacturer (Rotax)???? 

 

Many of the early Rotax 912's, that used an appropriate oil, are still going today & still using  the same oil, that meets the above specifications.

 

😈

[Blueadventures]

26 minutes ago, skippydiesel said:

I didn't want this Thread to be about oil, but if you cant beat the divergents, you might as well join in.

 

 

"......blend of Sport Plus 4 was altered by shell, black bottles to the red bottle."

 

Do you know for a fact ,that the Sport Plus 4 Black Bottle oil, was chemically any diffrent to what was in the Red bottle?

 

FYI: When talking oils its usual to use the term  formulation, blending is what they do with wine, whiskey, cake mixes etc.

 

What is "...inappropriate..." about using an oil, which meets/exceeds the specifications set by the manufacturer (Rotax)???? 

 

Many of the early Rotax 912's, that used an appropriate oil, are still going today & still using  the same oil, that meets the above specifications.

 

😈

You prove me wrong.

[skippydiesel]

Dear Blue - You made the claim (s). The ball remains in your court, never to leave it, until you demonstrate the truth (?) in your words.😈

Edited 8 hours ago by skippydiesel

[walrus]

The manufacturers lubrication recommendation may have nothing to do with "performance" in the power or reliability sense of the word, in fact it may even be sub optimal from a performance viewpoint.

 

For example, it is already acknowledged  in certain automotive circles that low viscosity oils are often specified to help meet cold start emissions requirements when in fact something heavier may be better for longevity. However there are conditions that we know nothing about that my make oil choice less obvious, for example foaming, behaviour of oil drainage systems or dry sump systems or pump cavitation, etc. We have to trust the manufacturer or do research ourselves.

[Blueadventures]

1 hour ago, walrus said:

The manufacturers lubrication recommendation may have nothing to do with "performance" in the power or reliability sense of the word, in fact it may even be sub optimal from a performance viewpoint.

 

For example, it is already acknowledged  in certain automotive circles that low viscosity oils are often specified to help meet cold start emissions requirements when in fact something heavier may be better for longevity. However there are conditions that we know nothing about that my make oil choice less obvious, for example foaming, behaviour of oil drainage systems or dry sump systems or pump cavitation, etc. We have to trust the manufacturer or do research ourselves.

I suspect the reason Shell changed the Sportplus4 blend 12 or so years ago was due to the effect on the gearbox performance, at the time I thought it was a bit poor that they did not change the brand name (reckon they should at least called it Sportplus4 extra or something to distinguish it from the earlier blend that was in a black bottle and no longer suitable.  This then saw the automotive similar grades now being not suitable anymore.

Edited 6 hours ago by Blueadventures