A mobile fuel filter for removing sulfur-containing compounds from a diesel fuel is provided. The mobile fuel filter comprises: a filter median comprising an absorbent for removing sulfur-containing compounds from the diesel fuel, the filter median being in fluid communication with a storage device, the storage device having a holding capacity greater than 1000 gallons and being configured for storing the diesel fuel, the absorbent being configured to remove sulfur containing compounds from the diesel fuel to produce filtered diesel fuel having less than 15 ppm of sulfur containing compounds, the absorbent comprises an inorganic oxide having a surface acidity characterized by a pK.sub.a of at least -3.