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_51289 ( "Driver" text, "Constructor" text, "Laps" real, "Time/Retired" text, "Grid" real )

### Question ###
When the laps are 31 and the constructor was honda, what's the sum of all grid values?

### Accurate SQL ###

SELECT SUM("Grid") FROM table_51289 WHERE "Constructor" = 'honda' AND "Laps" = '31'