Apologies Simon, but regrettably, I cannot offer any advice on this from a personal experience point of view.
Unless I’m confusing this with another older product, this used to be sold as an oil additive in the days when I had hair. Possibly now an actual oil brand-?
If so, my only comment would be, is that I’ve always stuck with VAG’s oil brand - Quantum - to good effect over many years, and I really don’t see me departing from that regime, along with good quality (generally German) branded filters.
The claim ‘… hugh difference to his oil consumption…..’ seems odd, since generally vehicles subjected to regular oil changes don’t have such an issue ( certain years, and component design changes excluded).
What will be your anticipated annual mileage Simon, and what will be your servicing routine?
Sorry I can’t help you more with this.
Kind regards,
Gareth.