Your comment, "my interest is more whether we can make machines waste less energy due to a lower friction and how such things can get realized" provoked me to respond:
On an initial thought, a fluid with no viscosity should be great because it means that there's no friction, right? I'm assuming this is your train of thought.
The flaw here is that there's no viscous friction - lubricants "want" a low viscosity because viscous friction causes the lubricant to heat and thus draws power from the system, but at the same time a lubricant needs viscosity because lubrication relies on thin films between the load-bearing surfaces to lubricate.
The viscosity of the lubricant is what keeps the lubricant from spraying/rushing out from between the load-bearing surfaces. In light load applications the lubricant is typically a very light, low viscosity oil, like WD-40.
As the design loads increase, the required viscosity of the lubricant increases. I don't know how much automotive experience you have, but there's a noticeable difference between engine oil and the gear oil in a manual transmission. As loading continues to increase thickeners begin to be added to the oil, producing grease.
So, back to your question, if you tried using a zero-viscosity fluid as a lubricant you would find that it would shoot out from between the parts to be lubricated as soon as you applied any load because there is no viscosity present to slow the fluid from leaving the joint.