Fuel sending unit for fuel-type detection

1. A method for fuel-type detection comprising:

placing a fuel sending unit in a first position from a second position, the second position indicating a fuel level;

releasing the fuel sending unit from the first position such that a buoyancy characteristic of a fuel sending unit float prompts the fuel sending unit to the second position;

sensing a rate-of-travel of the fuel sending unit from the first position to the second position to produce fluid travel data, the rate-of-travel being affected by a fuel density; and

generating fuel-type identification data based on the fluid travel data.

2. The method of claim 1 , wherein the placing a fuel sending unit in the first position from the second position comprises actuating a servo operably coupled to an arm of the fuel sending unit.

3. The method of claim 1 , wherein the generating the fuel-type-data from the fluid travel data further comprises:

accessing a look-up table indexed by the fluid travel data.

4. The method of claim 3 , wherein the accessing the look-up table further comprises:

sensing an ambient temperature to produce ambient temperature data; and

accessing the look-up table being further indexed by the ambient temperature data.

5. The method of claim 1 , wherein the sensing the rate-of-travel of the fuel sending unit from the first position to the second position to produce fluid travel data comprises at least one of:

sensing a variation in resistance, via a variable resistor of the fuel sending unit, over time; and

sensing a change in current, via the variable resistor of the fuel sending unit, over time.

6. The method of claim 1 , wherein at the second position the fuel sending unit float experiences a null net force.

7. A method for fuel-type detection for a vehicle engine comprising:

sensing a trigger event for the fuel-type detection;

placing, in response to the trigger event, a fuel sending unit in a first position from a second position, the second position indicating a fuel level of a fuel of a plurality of fuels;

releasing the fuel sending unit from the first position such that a buoyancy characteristic of a fuel sending unit float prompts the fuel sending unit to the second position;

sensing a rate-of-travel of the fuel sending unit from the first position to the second position to produce fluid travel data, wherein the rate-of-travel is affected by a fuel density of the fuel;

generating fuel-type data of the fuel based on the fluid travel data; and

selecting a base map setting for a vehicle power train based on the fuel-type data.

8. The method of claim 7 , wherein the trigger event comprises at least one of:

a vehicle refueling;

a sensed vehicle ignition key;

a sensed vehicle door opening;

a predetermined time period; and

a random time period.

9. The method of claim 7 , wherein the placing the fuel sensing unit in the first position from the second position comprises actuating a servomechanism operably coupled to a fuel sending unit arm.

10. The method of claim 7 , wherein the generating the fuel-type data from the fluid travel data further comprises:

accessing a look-up table based on the fluid travel data.

11. The method of claim 10 , wherein the accessing the look-up table further comprises:

sensing an ambient temperature to produce ambient temperature data; and

accessing the look-up table being further based on the ambient temperature data.

12. The method of claim 7 , wherein the sensing the rate-of-travel of the fuel sending unit from the first position to the second position to produce the fluid travel data comprises at least one of:

sensing a variation in resistance, via a variable resistor of the fuel sending unit, that corresponds with a movement of the fuel sending unit float from the first position to the second position; and

sensing a change in current, via the variable resistor of the fuel sending unit, that corresponds with a movement of the fuel sending unit float from the first position to the second position.

13. The method of claim 7 , wherein at the second position the fuel sending unit float experiences a null net force.

14. A fuel sending unit for fuel-type detection comprising:

a fuel sending unit arm operable to be coupled at a first end to pivot between a first position and a second position;

a fuel sending unit float coupled to a second end of the fuel sending arm for indicating a fuel level, the fuel sending unit float having a buoyancy characteristic to prompt the fuel sending unit arm to the second position;

a servomechanism coupled to the fuel sending unit arm, wherein the servomechanism is operable, in response to a command, to:

place the fuel sending unit arm in the first position; and

release the fuel sending unit arm from the first position such that the buoyancy characteristic of the fuel sending unit float prompts the fuel sending unit to the second position; and

a variable resistor coupled for varying a resistance value relating to a position of the fuel sending unit arm via the fuel sending unit float, wherein the variable resistor is communicatively coupled to a terminal, the terminal for sensing the resistance value over time to produce rate-of-travel data relating to movement of the fuel sending unit arm from the first position to the second position.

15. The fuel sending unit of claim 14 , wherein the rate-of-travel data operates to identify a fuel type.

16. The fuel sending unit of claim 14 , wherein the rate-of-travel data and ambient temperature data operate to identify a fuel type.

17. The fuel sending unit of claim 14 , wherein the variable resistor is coupled to the first end of the fuel sending unit arm.

18. The fuel sending unit of claim 14 , wherein the servomechanism further comprises:

an output shaft coupled to the first end of the fuel sending unit arm, wherein in response to the command, the output shaft is positionable at the first position.

19. The fuel sending unit of claim 14 , wherein the rate-of-travel data is based on at least one of:

a rate of change in resistance over time from the first position to the second position; and

a rate of change in current over time from the first position to the second position.

20. The fuel sending unit of claim 14 , wherein at the second position the fuel sending unit float experiences a null net force.