I have always used the FL-400s or equivalent on my 2001 Focus with Ztech engine per the owners manual recommendation. Recently I have seen the FL-2005 being recommended for the Ztech. What's the difference? When/why did it change?
The Zetec engines need the 2005 for the much more robust anti-drainback setup to help eliminate start-up rattle.
The FL-2005 and FL-400 are just about if not the same size. We always use the 2005 at my dealership and on my Fiances 2001 Zetec Focus. The last owner had a freak'n FRAM on it and when it sat for a day or two it rattled bad on startup until the oil pressure and was stabilized and refilled the block. YUCK!!!
The proper filter for the Zetec is the FL2005. The owners manual can be confusing. The single cam 2.0's get the FL400. Stick with the 2005, and you'll be happy for a long time. Your 01 can also run 5w20 if you choose. A good engine.
