What are the likely causes of excessive fuel consumption?

bad timingbad sparkplugslow octane fuel*malfunctioning coolant temperature sensorblocked catalytic converter(s)malfunctioning MAP/MAF sensorsbad driving habit (driving with the parking brake engaged)having aftermarket wings on the car.tyres not inflated to the recommended pressure

faulty oxygen sensor,leaking injectors,foul spark plugs,defective catalyst,air leakages in the exhaust system,bad driving habit

spark plugs good use orignal quiltyt