should nt use it in a car - certainly not for the major brands. At the loading gantry they put additives in which help meet their own quality standards. I have always gone for Shell or Chevron as these are richer in detergenets which help keep the engine cleaner and actually do have a beneficial effect to economy. In the US Shell are now advertising the gains - they havent been brave enough over here yet, but they have fuel comparison tests for various vehicles and gasoline (petrol). Redex can also throw the balance of lubricant additives as well.......