Poor Fuel Effiency on 1999 Toyota Tercel

I have Toyota Tercel 1999 1.3, autometis transmission, driving in Dubai, UAE. I am facing the problem from Fuel cunsumption that I am getting on 8KM/ L . Please Let me What should i do.

Asked by for the 1999 Toyota Tercel
Are there any warning lights on? I don't know what that vehicle is equipped with, but here in the states we have an onboard computer that monitors the engine for problems like this, and when it detects an issue, it will store diagnostic trouble codes. Those codes need to be retrieved to make a diagnosis.