You will be wasting your money. A good oil will stay within spec for the rated service life. The previous owner of my car stretched some of the services to beyond 20kkm (15kkm rated), and the car is on 280+kkm, with no issues, still original turbo.
The thing with the older oils was, that they broke down quicker due to contamination, heat etc. Modern oils are designed to live longer, and in conjunction with lower (50ppm) diesel, this is very much possible.