gas tank...theres no reason to have it changed regularly...as my mech says, the fuel filter can last as long as the car as long as u buy gas from well known places that are popular and u never run ur tank dry...the filter for our cars comes with the fuel pump at TRDsparks.com and cost $600+http://www.trdsparks.com/displayparts.php?Mdl_dtl=676&Part_cat=30&parts_id=3631