I know its been addressed but here it goes,

I have a 97 Johnson 150 ficht that has always been run with the evinrude ram ficht oil, with no problems. My question is.......

Should I continue with the xd-50 and if so should I use some kind of attitive like Carbon guard or

should I use xd-100 and if so Do I need to reprogram the engine ?

Not worried about cost, I just want what is going to be best for the engine.
The engine has a total of about 180 hours on it, and i probably will put no more than 75 hours a season on it. New to the board, thanks for all the help.