Rule 301.7 · Artifacts
Some artifacts have the subtype “Vehicle.” Most Vehicles have a crew ability which allows them to become artifact creatures. See rule 702.122, “Crew.”
Subrules
Each Vehicle has a printed power and toughness, but it has these characteristics only if it’s also a creature. See rule 208.3.
If a Vehicle becomes a creature, it immediately has its printed power and toughness. Other effects, including the effect that makes it a creature, may modify these values or set them to different values.