I am facing an issue of bad fuel average(8/9 km/L) inn my honda civic manual 2013, I have tried everything like getting catalytic converter cleaned throttle body cleaned fuel pump cleaned, the spark plugs are fine, oxygen sensors are even fine ,tyre size is 195/65 R15, I put 5w30 oil grade in the engine. I dont get the reason of bad fuel average, I drive the car with a light foot and one last thing I use hioctane fuel .Can anyone please help me what should I do to get a good fuel average.