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_23840623_4 (epa_rated_combined_fuel_economy VARCHAR, operating_mode VARCHAR, dirty_electric_grid_rocky_mountains__denver_ VARCHAR)

### Question ###
What is the epa rated combined fuel economy for the all-electric vehicle with dirty electric grid rocky mountains (denver) of 330 g/mi (205 g/km)?

### Accurate SQL ###

SELECT epa_rated_combined_fuel_economy FROM table_23840623_4 WHERE operating_mode = "All-electric" AND dirty_electric_grid_rocky_mountains__denver_ = "330 g/mi (205 g/km)"