I would never try it. Often those oils are the wrong viscosity, made with a really cheap base stock.
For sure. In addition to wrong viscosities, they have other issues such as contaminants.
A co worker of mine says you can use a cheap oil and fortify it with an additive and make it as good as a quality oil. I disagree.
And you would be correct.
I just ordered a chicken and an egg from the Internet; will let you know which came first.