The Volkswagen Fuel Injectors mounted in your engine are capable of spraying an atomized allotment of fuel so it can be easily mixed with the air in the fraction of a second. The capability is only possible when the fuel is as clean and free of particulates as possible.
Inside of every Volkswagen fuel injector are many small passageways that the fuel has to travel in before it reaches the end of the nozzle. If any foreign particulates are present in the fuel, it is these passageways that become obstructed and prevent the atomized spray of fuel from being produced by the fuel injectors. This is why it is emphasized that every Volkswagen has a new fuel filter installed on them annually. This will help to prevent and accidental clogging of the fuel injector as much as possible.
Not only are particulates a hazard and problems for the fuel injectors but also the coating of the inside channels with residue. This residue is very thin but in time will buildup in the channels of the fuel injector of the Volkswagen causing it to have a reduced flow of fuel to the end of the fuel nozzle impairing its ability to spray fuel into the combustion chamber. This is why the placing of a can of fuel injector cleaner in every fifth tank load of fuel is recommended and needed.
When the injector cleaner is regularly used and fuel filters are replaced on time, the insides of the injectors will remain clean and unclogged in your Volkswagen engine. This allows for the best possible performance and mileage from your vehicles power plant at all times for the benefit of the owner to utilize.