The major problem with this approach is that more than 50 percent of all mechanical engine wear occurs during the first few minutes after start-up while oil is still being pumped up from the oil pan to vital engine parts. And since modern engines have closer engineered tolerances and operate at higher temperatures and RPM's, even a small amount of wear is significant. Viscosity improvers simply make oil thicker. These products do not significantly reduce wear or increase efficiency. They may even disturb the chemical balance of your motor oil.
Excessive viscosity can even damage engines.
However, these substances were never intended for use in automotive engines due to their inherent corrosive nature. In modern engines, these products are less effective since these metals have been replaced with aluminum, titanium and other advanced alloys. In addition, they must be replaced at every oil change since chlorine molecules are easily removed from metal surfaces, and they have a tendency to evaporate. The waste oil may even create a toxic disposal problem. Engine treatments that contain solid particles suspended in a carrier oil are classified as colloids .