Patent ID: 7188614

Claim:
A petrol saving structure of a motor vehicle, comprising (a) an inlet by-pass pipe; and (b) an oxygen-detecting voltage controlling device connected to the inlet by-pass pipe; the oxygen-detecting voltage controlling device including: an air filter positioned next to an air inlet for filtering air; an electromagnetic valve; a controlling circuit board, the controlling circuit board being electrically connected to an engine computer by means of a plurality of controlling signal wires such that a current rotating speed value of an engine will be sent to the controlling circuit board through the controlling signal wires; the controlling circuit board being provided for sending a stable voltage through the controlling signal wires to the engine computer so as to stop the engine computer from making correction by increasing amount of petrol injected through an injection nozzle; and a start adjustment knob electrically connected to the controlling circuit board for setting a first engine rotating speed value; the controlling circuit board being going to be activated and start sending a stable voltage to the engine computer as soon as a rotating speed of the engine reaches the first engine rotating speed value; a stop adjustment knob electrically connected to the controlling circuit board for setting a second engine rotating speed value, which is greater than the first engine rotating speed value; the controlling circuit board being going to be turned off and stop sending a stable voltage to the engine computer as soon as a rotating speed of the engine reaches the second engine rotating speed value.