or a year? Oil filters for the Zetec engine are hideously expensive, if you can even find them in the first place. Wix is the only manufacturer of Zetec filters that are actually sold in stores (buying online means expensive shipping). Part number 51315 (Napa Gold 1315) The Napa Gold 1315 is $7.69, and the Platinum is $12.49, The Silver is on sale for $4.03 (regular price $5.29) Fram doesn't make an Ultra XG8316 (the only Fram worth buying), and the lower Frams (Soft Guard and OCOD) why even bother. Plus, nobody even carries the TG8316. The Mobil 1 M1-211 isn't sold in stores (online-only) Nobody on the east cost seems to carry Baldwin or Hastings. Which leaves Wix/Napa, but they cost more than normal due to a special design for the Zetec (which is also why Purolator has all but discontinued the PL25230, no more Motorcraft FL-2005) So, is Napa Silver durable enough to last an entire year? Oh man I wish the Platinum would go on sale for $7.54 again!