Even with top tier fuels you can still get dirty injectors and poor spray patterns at the nozzle over time. Besides, the Lucas stuff is almost useless and will not hurt a thing if you overdose. Its not really a cleaner at all, and mostly adds a light oil to the fuel for a Top end lube. If you want to truly clean up your injectors, get something with a high dose of PEA like RedLine or Regane.