My question is, how good is the cleaning power of the full syn? I know it is similar to synpower, but have never used anything but maxlife in my car, but see no reason for it really. I have been experiencing a bit of a vvt-i tick noise in my 2007 toyota yaris, so I figured I would step down to a 5w20, and a strong cleaning oil. I'm thinking of running Napa full syn w/ their gold filter for about 5k miles, since it ends up only being $23 total. Any thoughts?