I saw that Wheeler Dealer episode a few years ago. Very impressive results on that older Jag. Better than adding a can of Seafoam to the gas tank or directly into the manifold. Not sure about cost. The downside however is that it will have minimal benefits on a DI engine. It will have no effect on the upside of the intake valves and intake ports. Not a solution to DI induced carbon build-up.
After seeing my valves when I installed my IM I don't need any additives. My valves are perfect. This would only be needed on a neglected engine, or one that had poor fuel quality.
im pretty sure my cars engine was taken care of. im the 2nd owner and i have all the maintenance records and all history. but either way.....if i was to get it done..it couldnt do any harm could it? in the long run?
After seeing my valves when I installed my IM I don't need any additives. My valves are perfect. This would only be needed on a neglected engine, or one that had poor fuel quality.