DTE thing is being

now!
Here is the patent information. GO FIGURE.
Apparatus for indicating distance to empty of a vehicle, and a method thereof - US Patent 6961656 Claims
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1. An apparatus for indicating an initial distance to empty at completion of fueling of a vehicle, comprising:
first means for detecting an amount of fuel in a fuel tank;
second means for detecting if a fuel tank lid is open or closed;
third means for detecting the vehicle speed;
fourth means for calculating a fluctuating fuel consumption rate based on information from the first means, second means, and third means, and calculating an initial distance to empty available from the fuel at completion of fueling based on the fluctuating fuel consumption rate and a predetermined fixed fuel consumption rate; and
fifth means for displaying the calculated initial distance to empty,
wherein the fluctuating fuel consumption rate is derived from calculation of traveled distance divided by amount of fuel consumption between previous closing and current opening of the fuel tank lid, wherein the calculating the initial distance to empty comprises:
calculating the first distance to empty based on the predetermined fixed fuel consumption rate and the amount of fuel;
calculating the second distance to empty based on the fluctuating fuel consumption rate and the amount of fuel;
calculating a compensation value defined as the first distance to empty subtracted by the second distance to empty; and
calculating the initial distance to empty by calculation of the second distance to empty subtracted by the compensation value.
2. The apparatus of claim 1, wherein the fourth means comprises a central processing unit operated by predetermined software, and a memory storing data processed by the central processing unit, the predetermined software being programmed to execute instructions for:
determining if the fueling of the fuel tank has started;
calculating, when the fueling of the fuel tank has started, a fluctuating fuel consumption rate by calculation of traveled distance divided by amount of fuel consumed between the previous closing and the current opening of the fuel tank lid;
determining if the fueling of the fuel tank is completed;
determining, when the fueling of the fuel tank is completed, the amount of fuel; and
calculating the initial distance to empty available from the amount of fuel at completion of fueling based on the fluctuating fuel consumption rate and the predetermined fixed fuel consumption rate.
3. The apparatus of claim 1, wherein the fifth means for displaying is a liquid crystal display apparatus.
4. A method for indicating an initial distance to empty at completion of fueling comprising:
determining if fueling of the fuel tank has started;
calculating, when the fueling of the fuel tank has started, a fluctuating fuel consumption rate by calculation of traveled distance divided by amount of fuel consumption between completion of previous fueling and start of current fueling;
determining if fueling of the fuel tank is completed;
calculating, when the fueling of the fuel tank is completed, the amount of fuel; and
calculating the initial distance to empty available from the fuel at completion of fueling based on the fluctuating fuel consumption rate and a predetermined fixed fuel consumption rate, wherein the calculating the initial distance to empty comprises:
calculating the first distance to empty based on the predetermine fixed fuel consumption rate and the amount of fuel;
calculating the second distance to empty based on the fluctuating fuel consumption rate and the amount of fuel;
calculating a compensation value defined as calculation of the first distance to empty subtracted by the second distance; and
calculating the initial distance to empty by calculation of the second distance to empty subtracted by the compensation value.
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Guys, just like your laptop/camera/camcorder battery info is provided and keeps changing based on usage/no. of application open etc, ditto here.
What ruchir says makes sense..just like a compute is booted up first time, it should show the initial estimate (which is always the max charge left), and subsequently depending on usage, the remaining charge is calculated in real-time basis..which always is lower than the first estimate.
This seems to be true when the engine is cold started - I have noticed the DTE figures to be highest during the entire day - and subsequently keeps on varying between x & y, where x/y is never higher than the initial DTE estimate.
I am searching for a OBD-II reader which can be plugged-in the OBD port (under the steering wheel in Fiesta & front left bottom door in Ikon) and realtime analysis of the vehicle condition can be had on a laptop using suitable software. This is the same port which the service center guys use for ECU reset/mapping etc and to know the vehicle conditions/troubleshooting. Ordered one-such dongle with bluetooth from dealextreme but the item was out of stock. Will be sourcing soon for my carputer project for Fiesta. Search for "carputer" in tbhp for more info.