As has been discussed before, they're just trying to drum up interest off the back of the performance petrols.
The problem is that the petrols have a real, tangible improvement in that they're a higher octane rating and engines which can adjust their timing to suit will definitely benefit from this.
This can't be done with diesels so they have to resort to weird additives and other crap which supposedly improves the performance but I've yet to see a single independent test which verifies any of the claims for the performance diesels so I think it's all just marketing guff.