You can use Redex Petrol System Cleaner as often as you like to clean your car’s fuel injectors and fuel system. Typically, we recommend adding a dose of cleaner each time you fill up the tank to make sure your engine is clean and maintained.
Each bottle of Redex Petrol System Cleaner contains two recommended doses of cleaner. Don’t worry, though, using too much Redex won’t damage your car or lead to any long-lasting side effects. So, it’s safe to use as and when you need to clean your car’s fuel injectors.