Yes, some by-pass filter canisters drained almost to the bottom and some did not. Fram made a "Sludge Siphon" to remove the oil and gunk that did not drain from the bottom of some of its canister filters.
Yes 10W-30 means equivalent to 10 weight oil when cold and equivalent to 30 weight oil when warm. Therefore straight 30 weight oil and 10W-30 weight oil would have about the same viscosity when warm.
