Coming up on my 1000 mile service on 15 RG Special. I have been given 2 different stories on going synthetic yet or not. One says wait till 5000 mile and convert if I want to and another says go ahead and do it now. Taking the $$ out of the equation, do I go Syn now or wait? I am not so much sold on the Syn blend myself. Have always ran regular in all 3 holes in years past with no issues.