Re-refined oil as base oil for lubricants

[mikkhh]

Stumbled upon some news that Castrol is going to supply re refined oils for Renault vehicles.

Due to carbon footprint re refined oils might even become mandatory.

https://www.castrol.com/en/global/corpor...-rrbo.html

Here is the questions is re refined base oil something to be afraid of? Or is it something that can be good deal provided the oil is cheaper than conventional? Has the re refined base oil be mentioned on product sheets and on package?

What about Delo oils, local dealer here is giving really really good price for those oils, competitive oil sellers mention that those cheaper oils use re refined base oil and just keep bashing others, no reason why their competitions product is not good, ZERO facts given.