Bought the Royal Purple oil change deal @ Pepboys, 1st time using RP.
2005 Taurus 3.0 U
RP filter.. #20-400
5W-20 RP oil.
Engine has 63,000 miles.
Previous oil was Castrol Edge w/t, gold bottle, 5W-30.
I have switched back & forth from 20W & 30w, and have experienced no difference for the most part.