CREATE TABLE table_31160 ("No." FLOAT, "#" FLOAT, "Episode title" CLOB, "Director" CLOB, "Writer ( s ) " CLOB, "U.S. original airdate" CLOB, "Prod. code" FLOAT)

When 'speed metal' is the episode title what is the lowest number?
SELECT MIN("No.") FROM table_31160 WHERE "Episode title" = 'Speed Metal'
SELECT MIN("No.") FROM "table_31160" WHERE "Episode title" = 'Speed Metal'