Recently under 'historical anecdotes' I posted the following:
Peugeot placed istelf on the map in Australia in 1953 when a 203 won the first round-Australia reliability trial.
Your post reminds me that that event was sponsored by Redex - at the time in Australia it was called the 'Redex trial'. I did not mention this because I thought the product (which neither I, nor anyone I know, has ever used) was long-forgotten. Wrong!. Apparently there are some 'snake oil' users out there.
Regardless of any actual merits, anyone who can persuade a significant number of people to use a fuel additive can make a lot of money. I have always taken the view that if an additive was worthwhile it would be adopted by one of the major fuel brands as a marketing ploy. Another test is whether the vehicle manufacturer recommends any additive.
Recently in Australia a variation on the .'snake oil' thing has emerged
- it is called after sales - when you sign to buy a new car you are passed to a pretty lady who attempts to sell you a whole raft of things
- coatings for the paint, the upholstery, the chassis and snake oil additives to fuel which are said to do all sorts of things essential to the wellbeing of your new vehicle. All crap! Exploiting a new vehicle owner while in a vulnerable state.