filled up the tank and the gauge shows 3/4 of a tank... any suggestions

You don't say how old your car is. But sometimes the sensor gets dirty and will not read accurately. Could also be the gauge. You can tell by shorting the sensor connection to ground. If it goes to full, its the sensor. If not, its the wiring or gauge. What does it read when the low fuel light comes on?: That is the most important indication.

sorry about that i got a 94 Ex and the low fuel light hasnt come on yet but ive been on E(according to the gauge) for the past two days.

As for the low level light, you could have burned out light, bad wiring, a bad sensor (it is a different sensor but in the same module inside the gas tank) or enough gas in the tank so the sensor is not lighting. You can test the light by shorting the sensor to ground. Black wire is ground on Hondas.

ok. preciate the replys. how many miles on a tank should i expect to get on an auto stock 94 accord???? 300+?

About 350 highway miles per tank. About 325 around town miles.

'91 Accord LE 260,000 Kms.

300 to a Tank ?? You're not using Acetone obviously. The side effects of it are 10-25% increase in gas mileage. Cleaner engine, gas tank float/gauge/lines, and injectors, AND lower emissions/smell.
Plastic/rubber parts have been exhaustively tested.

http://www.timebomb2000.com/vb/showthread.php?t=143848

I recently did a 120 mile mixed drive, 90 hiway. I used to get 28 mpg. This day on refilling after the trip I recorded 41 mpg, or 570 to a tank ! It was the first cold day of the year too. Not ideal conditions, as a cold engine is less efficient. Couldda got maybe 45 mpg lol.

What you need: 1-3 once measuring cup $1, Acetone $4 per quart, and a long necked funnel $3.

1 ounce per 5 gallons, that'd be 3 ounces for an Accord. (14 gallons)
Fill the tank to the first click, and do the same when you want to check your gain in mpg. It takes some calculating for some cars , but the Accord seems primed for this stuff. My 91 Regal saw no change to be honest, (not sure of size of tank) used too little. Cost per gallon is 10 cents what you gotta lose!

Some of my figures may be off as I'm in Canada and our Gallon is the larger Imperial. You will find orignal specs, US sizes/mpg on the "consumers site".

BTW, ALL Octane/Mpg boosters ,and Premium gas contain Acetone,or a dirivitive. (but they ain't tellin you that)

twincougars' pseudo scientific post at the link you gave is full of absurd inaccuracies. For example, a 30% difference in gas mileage between the "best and the "worst" gas stations? Nonsense.

On that basis, why should we believe anything he says?

And I'm sorry, dreager - while I am not going to risk the damage that acetone could cause to various components to try it, I have a REALLY hard time believeing that your mileage went from 28 to 41 by putting 3 ounces of acetone in a tankful. There aren't ANY gas additives that claim anywhere CLOSE to a 46% improvement in gas mileage.