The fuel filter is not serviceable, it is in the fuel tank. There are no spark plug wires, it is coil on plug ignition. Folks don't just throw suggestions out there unless you are sure of them. You will just cause the guy to chase problems that don't exist.How many miles on the car? Auto or manual shift? Find kilometers per litre by filling up the car & set the trip odometer to zero. The next time you fill up divide the liters used by the km driven....is this how you are doing it? Do you drive far enough to get the engine to operating temperature or very short trips?AHAH!!!!!!!! Your math is the problem perhaps? Here's the conversions I got:Kilometers Per Liter Miles Per Gallon (U.S.) Miles Per Gallon (U.K.) KPL 13.00 = US MPG-31.07 UK MPG-36.72According to this you are getting 31 miles per gallon in the city which is exceptional to say the least. I suggest you fill up again and recalculate double checking the conversion to MPG.