What class of car had the XI Coppa Acerbo title?
CREATE TABLE table_name_31 (class VARCHAR, race_title VARCHAR)
SELECT class FROM table_name_31 WHERE race_title = "xi coppa acerbo"
### Context: CREATE TABLE table_name_31 (class VARCHAR, race_title VARCHAR) ### Question: What class of car had the XI Coppa Acerbo title? ### Answer: SELECT class FROM table_name_31 WHERE race_title = "xi coppa acerbo"