The phrase "one's fuel economy ratings" refers to the measurement or evaluation of how efficiently a vehicle uses fuel to run. It tells you how many miles per gallon the vehicle can travel, indicating its fuel efficiency. Full definition
It will come with combined fuel economy rating of 33 mpg. (suvtrend.com)
Both engines get an estimated fuel economy rating of about 35 combined mpg. (japanesesportcars.com)
Both models offer a claimed combined fuel economy rating of 21 mpg, very impressive but hardly likely to be achieved if they are driven as intended. (carbuzz.com)