Probably the most glaring difference is the size of the OEM oblong shaped intake hose end piece (left) vs. the 3" silicone hose. The OEM parts restricts a lot of air before it even gets to the filters. The hose has to be squeezed to get it through the exit openings on either side of the radiator, but still allows for greater flow and can be extended further in front of the engine and radiator for cooler air.