Ok So... Build-a is a girl. She was built alone, with no one else and no humans left in the world. She doesn't really stop and wonder much yet, but she does get easily distracted like an excitable kid. She doesn't think there are issues with her in the comic yet as there were originally no other build bots to compare herself too. But the other build bots have no personality, they are simply robots. She is just a gal who wants to build... but was told by Query she has to get things going on fixing the long neglected factory first.
No preference on oil.
EDIT: Link to our comic is in the profilings if you want to read it