0.o wow, that is really bad, does the computer say that or did you mathmatically come up with it? and do you have the roof display?

 

I figured that out just by doing the math...the roof display is saying 23 but they isn't right...how accurate is that display anyhow

 

pretty accurate, so i would assume maybe your loosing gas somewhere before it gets to the cylinder. maybe your leaking somewhere

 

They did a pressure check n couldn't find anything... I'm stummped

 

reset your fuel used when you top off your tank and see how close it is the next time you fill up as to how much gas it says you have used. it should be really close because of the computers calculations, i know mine is

 

Would the computer be more accurate than the gauge itself cause I believe I've done that b4 and as far as gallons used differs from the gauge..like a lot it will say like 1 gal used but my gauge is already at the line right after full... it could be my sending unit...that's what I'm thinking cause I was at half tank a few days ago n went to fill it up n it stopped at 5.5 gal.. seems to be off by 2 gal n when I turned the car on it was right above full but within about 5 min it already started to move like almost a whole line... now besides e half and f what do the other lines mean like if its at the line right about f what does that mean like how many gallons left?

 

gm are offset so you really cant tell the exact ammount of gallons, and if your trigger is bad, it wont tell you how much is left anyways

 

now what if my sending unit is weak and is saying I have low fuel and is about 2.5 gallons off will my car still shut off cause the comp thinks its outa gas even when its not?

 

no, you should be fine. it measures how much gas is used at the engine, not by the sending unit on the fuel pump. its just so you know how much gas is left.