Air filters such as the Malossi Red Sponge are usually only slightly more expensive than standard air filters, and they look cool – but is there an actual benefit?
Standard air filters on most 50cc scooters are a single compound sponge, usually fairly high density (the holes in the sponge material are very small) and around 20mm thickness. Over time these high density filters start to disintegrate into a powdery mess – which is why its important to check them at regular service intervals! While you can wash most standard air filters, as they start to wear they are easily damaged.
Performance air filters such as Malossi Red Sponge filters are different in a couple ways. The first is that all Malossi Red Sponge filters are fully washable. They can be washed in detergent, to clean out any rubbish they suck in or any old oil that has soaked into them (they need to be left to dry thoroughly after being washed). The second way they differ is the type of foam they are made from. Malossi have two different types of filter foams available in most of the replacement filters they offer – Red Sponge and Double Red Sponge. Red Sponge filters are made from a low density foam (larger holes) meaning they allow a higher rate of airflow. The kick back of lower density foam is that it doesn’t filter as finely. With this in mind, Malossi also their Double Red Sponge, which is made from two layers of foam. The outer layer is the same low density Red Sponge as the beforementioned filter, however the second/inner layer is a higher density foam, more similar to the standard filter foam. For a daily rider / commuting scooter, this is ideal. It allows the engine to breathe a little bit more freely, but still offers a great level of fine filtering.