I've ran Valvoline Conventional 10w30 in my car since day one and i've had no problems. Infact several in my family have taken motors to the 400,000+ mile mark with Conventional Valvoline oil. I like changing my oil oil every 2,500-3,000 miles OR (since it ain't a DD anymore) every 4-6 months. Oil doesn't stay fresh forever and can contaminate. I don't feel comfortable leaving oil in a vehicle 5,000+ miles, I never have. Call me old fashion, but as much as I like to change my oil, Synthetic would be a big waste of money for me for the Motor. The tranny, that would be another story. Oil is cheap and easy to change, and for me its piece of mind.
I'm not saying Synthetic is bad at all, I have no problems with it at all. I just think conventional can be just as good if used right, thats all i'm saying. For someone like me with his religious maintence schedule, conventional is right for me.
Also, highway miles are always better than street miles. My car was always a highway daily until recently. Anytime I drive it though, I like to take long trips with it.
