gas meter problem

[kman]

ok so being a student it its rare that i have a full tank of gas, i mean all the way to the right side.(at least for me not sure about other people). so yesterday i was helping my friend and his dad move some stuff from one of their house to their one of their other ones. after that i had to help bring a refrigerator into his sister apartment. so before we leave his house to go do that his dad asked if i had gas( there wasn't any room in his truck) so im like my car say's i have 35 miles left, meaning my gas will go on soon. so he's like stop at the gas station and ill get you some gas. we get there and he's nice enough to give me a full tank of gas. now heres the problem my obc is say that i have like 211-220 miles and that mean i have half a tank or a little over. i most times $10,$15,or $20 when getting gas. so do you think the gas sensor is maybe dirty or something? because it should be in like the 390's.

[drz]

WHat does your fuel gauge in the instrument panel show? If that dsiplay is correct, then your sensors are fine. If I am not mistaken, the OBC makes the calculations based on the fuel consumption at the time it is displayed. In other words, if you have 10 gallons in the tank and are driving at 20mpg, the OBC will display a range 200 miles. However, with the same 10 gallons left, if driving at 25mpg, the OBC would display 250 miles. I am pretty sure this is how it goes.

Again, if the fuel gauge works fine, then your sensors are fine.

[kman]

ok thanks