I use would use Mobil One or Pure-One Purolator (they make Subaru oil filters). These are good so is K&N. Now I use an Amsoil.com oil filter, they last 12,500 miles. The numbers are SDF-20, and they make one that is 1 inch longer the SDF-36. I use the sdf-36 because it allows more oil to flow and since it's larger it helps cool the oil.