I have another doubt, why "OLIVE"? Who suggested first it? Who choose it? On what basis? Could anyone help?
It is a good oil but probably is the LESS modifiable of all edible oils. This property, or better its stability may, be good for closed crankase engines, but it is not particularly interesting for open crankase engines, as 2 or 4 strokes model engines.
Maybe the old suggestion "use the cheapest and thickest oil" on the original paper for modifying conceals an important truth. Cheap polyinsaturated oils are more apt to improving at levels of viscosity higher than the olive one. In this case their negative alimentary quality turns to be useful for model engines.
Ugo