Not bring a post back from the dead but, I'm sure thre second # is the ammount of detergents in the oil. for example: 5W - 30 means 5weight - 30 detergent grade

detergents are used in engine oils to protect the level of viscosity and to help prevent thermal breakdown.

1998 Contour GL Zetec I4 w/auto MODS: Fog lights and Mesh grills Soon to come are a set of Rims and Yokohama AVS ES100's Come see at cardomain.com