Hey guys, I just scored some Rotella T Synthetic 5w-40 ( 18 quarts or exactly four changes )for $1.25 a quart tonight at wally's on clearence. I usually run Chevron 10w-30 summer and 5w-30 in winter at 3000 mile changes. My question " is the Rotella T OK to use in a 2002 3.4 chevrolet gasoline engine. If so what interval should I take it too, and would it be good at cleaning the engine. Thanks in advance for your comments.