i think it depends on car,i used it on bravo and it does make car abit more nippy,not sure 100% but i think it works by having a higher octane level than normal petrol,just like the rest of em,cheapest ive seen is sainsbury's super unleaded which has higher octane than sainsbury's normal,think it was 77.9 last time i looked,u can also buy bottles of octane boost for car which do the same thing
im sure im right in a way(for a change)