CHEVROLET OPTRA ENGINE POOR MILEAGE

Hello, I Have A Chevy 2005 1.6 Automatic Transmit Ion That Takes Alot Of Gas, I Checked It On The Computer And Everything Shows Its Normal...

Sir Gud Day. My Chevy Optra 1.6 At Only 6 To 7 Kilometers Per Liter. Somebody Told Me That Ecu Reflashing Can Help To My Fuel Comsumption....