i have been running regular oil and would like to switch over to royal purple syn. my question is can i just put in royal purple in on my next oil change with no problems. or is there some steps i need to take first?

 

all of the synjthetic oils I have seen lately can mix with regular oil without a problem, so drain it and switch to the synthetic of choice

 

im using 20w 50 castrol gtx. when i switch to royal purple should i continue using 20w 50??????????????

 

Since you are in a warm weather area 20-50 is fine. If the ambient temp gets below 60* I would think about a thinner oil 10-30 or 5-30(I use 0-30 in my race car during the early season). I would just make sure the oil has warmed up for a couple minutes before any hard driving. low oil temp can really be hard on engine bearings. keep using the oil grade you have been using and make sure the engine is at operating temp before any hard driving.