The new Mercedes-Benz Fuel Filter exceeds the level of purification that is now mandated by the new style of fuel injections systems. This increased level of purification by the fuel filters now being placed on Mercedes-Benz is required so the end of the fuel injectors can consistently emit an atomized spray of fuel into the combustion chamber.
The older style and types of fuel filters are still in use on the previous models. Their level of cleanliness is not requires since the carburetors and throttle body fuel injectors are not as sensitive to dirt and particulates that might be floating around in the fuel as the newer fuel injection systems are. Many of them also had the mechanical fuel pumps that were not as consistent in the pressure of fuel it could deliver as the newer electrical versions now on all Mercedes-Benz models.
One thing that should be noted about the newer Mercedes-Benz fuel filters and changing it is that the fuel pump used on this system today is of the electrical variety. On the older models, the fuel pump was of a mechanical version which only pressurized the system once the engine was running. The newer electrical fuel pump pressurizes the fuel system the instant the ignition key is turned on. As a safety precaution the key should be removed from the vehicle before the fuel filter's seals are broken and replacement is attempted.
With the newer more stringent specifications of the fuel requirements for the Mercedes-Benz vehicles, the fuel filters should be changed more often than in the past. This should now be at a minimum an annual event. It should also be changed out if bad gas or contaminated gas is every purchased and used in the vehicle.