Possibly a light weight turbine oil would be suitable like Zoomspout 10wt. (These are non-detergent) Automotive oils are usually multi-vis, anti-foaming, and high in detergents that degrade over time. Royal Purple has a great reputation but I have never found it in the quantities and weights I need for my particular small collection of TT. (Several TD-124 and a Scheu Premier II)
Since the main point of lubricants is to prevent/reduce metal-to-metal contact (and thus extend lifetime by many orders of magnitude), viscosity of a lubricant should be selected to the particular circumstances - slower moving and more pressure dictate more viscous lubricant so the lubricant film doesn't break down. There are also additives like graphite and molybdenum disulfide which are layered in structure and help prevent metal-metal contact. A thin oil is appropriate used for light pressure and fast movement in general, heavy greases with additives for constant pressure and slow movement.
In some applications minimizing friction is important, which means the choice of lubricant is a compromize between friction and lifetime. Acoustic noise from a bearing is also affected by viscosity as this acts to dampen vibrations.
But tribology is complicated, the nature of the materials, surface roughness, speed, pressure, lubricant all interact.
In some applications minimizing friction is important, which means the choice of lubricant is a compromize between friction and lifetime. Acoustic noise from a bearing is also affected by viscosity as this acts to dampen vibrations.
But tribology is complicated, the nature of the materials, surface roughness, speed, pressure, lubricant all interact.