Abstract: A portable navigation device is set out for calculating fuel related parameters and returning related data to the user of the device. The related data may include fuel cost of a particular calculated route. Additional data may include particular displays of information including a theoretical calculated volumetric amount of fuel used by a vehicle in traveling along a calculated route before, during or after completion of travel. Other displayed data includes a theoretical calculated financial cost of fuel used by the vehicle in traveling along the calculated route before, during or after completion of travel. Still further displayed data may include an optimal calculated route chosen from many possible calculated routes, the optimization occurring on account of the relative fuel cost of each of the calculated routes.