Because one if the automotive oils being hyped for TT use destroyed a low mileage/excellent condition Citroen engine (per my Citroen trained mechanic).
The oil manufacturer eventually admitted their product was not suitable for the engine, though you would not know this from their ad/spec copy.
Nothing special (;-) about the engine other than it being of 1960's design.
Better safe than sorry is why I avoid automotive and multi-purpose oils.
I use Singer "sewing" machine oil in Thorens decks (have since the early 1970's), but the SY TT bearing is different/unique with its stacked ball bearings.
The oil manufacturer eventually admitted their product was not suitable for the engine, though you would not know this from their ad/spec copy.
Nothing special (;-) about the engine other than it being of 1960's design.
Better safe than sorry is why I avoid automotive and multi-purpose oils.
I use Singer "sewing" machine oil in Thorens decks (have since the early 1970's), but the SY TT bearing is different/unique with its stacked ball bearings.