Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_58537 ( "Engine" text, "Power, continuous" text, "Power, takeoff" text, "Compression ratio" text, "Supercharger gear ratio" text, "Octane rating" text, "Dry weight" text )

### Question ###
Which supercharger gear ratio has a Octane rating of 68?

### Accurate SQL ###

SELECT "Supercharger gear ratio" FROM table_58537 WHERE "Octane rating" = '68'