Originally Posted By: Nick R
It doesn't really matter, but like most have said it's probably because of cost to customers. 5W-20 is available in conventionals. 0W-20 is synthetic only, and more expensive, especially for people who get their oil changed at dealers/quick lubes.
Nothing stopping you from using 0W-20 though, it meets Fords specifications. I use 0W-20 in my focus anyway as you can see.
Exactly. Nowhere in the Ford manuals, they say that you _have_ to use 5W20 synthetic blend. What you _have_ to use is the oil that meets Ford's specs. For the 20 grade oils, the spec name in the recent times was WSS-M2C945-A. For example, Mobil 1 AFE 0W20 meets this, as it is mentioned in the product manuals, as well as probably many other 0W20 oils. (Be careful though as some do not, even though they probably would be fine IMHO).