5W-20 oil?

[JFormantes@aol.com]

Dear Everyone,

I am the guy who posted this "5W-20 oil" thread.  I am very sorry... the
thread went bad.  The questions I asked since start, never got an answer.  Here
are my questions:

1. Can I use 5W-20 engine oil in our SR engines?

2. Does 5W-20 oil viscosity requirement were based on engine's tight
clearances?
( there's a guy here doubted that focus' engines, were in no way have tighter
than SRs or honda's engines. The gay said the focus use 5W-20 oil. )

Again  I am sorry...