I use Pennzoil Conventional and came across some old post of people discussing the color as compared to other brands. Got bored and dumped a little on a white paper plate, and then dumped some valvoline I had which I use in the lawnmower... The Valvoline is quite a bit lighter in color. I know enough that it makes no difference at all in the quality...but does Pennzoil use a different add pack that makes it darker?