are mpg computer accurate,im getting bad mpg

[lozz]

im lucky there, not seen or heard an ice cream van up here for years, it is rough up here tho mind!
perhaps they got busted for selling other things .

[codgod]

hi folks,since i posted this 1st post ive been doing brim to brim testing and the always gives me 40 ish mpg no matter how hard i drive it.the reason why i put the post on in the first place is my fuel gauge was going down pretty fast,but since ive been filling my car up every week the needle will go down to half a tank after about 200 miles then the needle will go up to 3/4 of a tank again.what is the proplem could it be the sender unit.any ideas,thanks steve.

[boombang]

If I park facing up my sloped drive it currently will say under 1/4 tank and 80 mile range. Parked it down the drive and shows 1/2 tank and 250 mile range (been towing so range is far lower than normal).

My MPG counter is 3MPG high every time.