Ok guys and gals i use Valvoline Syn Power 10W30 on my Titan as it is right now. But wanted to maybe switch to Mobil 1 synthetic, and was wondering if its better to switch over or is what I'm using good already? And yes the Valvoline I'm using is full synthetic so ill just be switching to another synthetic so wanted to see if there would be a prob doing so. My truck mileage is 41k so not to old. And yea one more question how long do i keep using 10w30? and what is next after 10w30 if i have to switch oil weigh?