snakeoil

Came across this via a friend in France, can't fathom how it works, perhaps one for the technically minded. It claims 300 Kilometers extra per tankful. Notre technologie - Eco-Leau Moteur Eau Pantone: Economisez du carburant grâce à l'eau ...

Just taken my car in for an mot. All good sailed though. BUT while I was there the technician commented on the engine being noisy... its always had that sound??. Any way he said to use slick50 on it. Have done some reading up and the majority of people say don't use it. So is there any other...