How can i Fix proper petrol consumption

Congrats on your purchase! First, are you getting any trouble codes from the computer or any other systems? Do you smell raw gas when you drive? Did you replace the engine with the same type of model that you have? If not, did you have the computer re-flashed to the current engines configureation. The Mileage you described does seem low. If there are no major mechanical issues present, I would do the following and then check the results: Plugs, Check coil-on-plug harness condition, fuel filter, and air filter. Good luck to you!

The 2006 Explorer probably has a sixteen to twenty gallon fuel tank (US). The rating on the vehicle is 14-19 MPG (US) 500KM equals 310 miles (US), so depending on driving conditions (city and highway) your previous mileage seems rights. (20 MPG with a 16 gallon tank and somewhat less with a 20 gallon tank). If you are not getting any trouble codes illuminated on the dash there could be internal codes not showing. Normal idle on a warmed up 4.0 is somewhere around 750. Is it much higher? YOu could also have a transmission problem - slipping. Does the engine have to overly rev when beginning to move from a dead stop? I suggest you have the codes read first at a shop which has a live feed engine analyzer. It will indicate electronic and other malfunctions. If no problems are found then they can check out the transmission.