So here's my situation....2002 Civic, BTW.

2 days ago I had about 1/4 of a tank of gas, so I figured I'd fill it. I put in about 12 gallons ($43 - yay), but I noticed at the time that 12 gal. is a bit more than what I put in usually. And usually, I have about 1/8 of a tank when I fill up. So 10, 11 gallons is what I normally put in.

Since then I've driven about 220 miles............and the gas meter says my tank's still full. Normally, I'm lucky to get about 80-100 miles before the meter starts coming down from the F. Heck, at the 200 mile point I'm at half a tank of gas.

And yet it still says full.

Now the gas meter DOES move - when I've started the car up today, it goes to about a bar or 2 below full - but as I drive it goes back up to full. And when I shut the car off, the gas meter shuts off completely and goes down to E - which is what's normal. So I'm not sure if it's a "gas meter broken" problem.

Car's been running fine, no signs of it running poorly. I just had some sensors replaced a couple weeks ago; and my catalytic converter needs to be replaced, but my usual mechanic and another one local says I can still drive the car and that it shouldn't negatively affect other elements of the car's performance (just the pesky environment - but I'm planning on getting a new car this summer anyway).

So is there some chance I somehow put a TON of extra gas in my car and it's still technically full? I don't know how (or even if) I can check manually, besides just relying on the meter on my dashboard.

Help?
Thanks.

I actually had the same thing happen to me not to long ago. After going about 250 miles my car said it had about a half a tank of gas left and I couldnt believe it so just to be on the safe side I went and filled it up and it only put somewhere around 7 gallons in the tank. I forget the exact numbers but it averaged out to me getting about 37mpg out of my si driving on the interstate at about 4-4.5k rpms. It usually gets around 27mpg. I dont know what happened but I didnt complain. I would just fill it up to check and see and make sure nothings wrong.

I had a silmiar thing happen to me recently as well with my 2004 Civic Si.

According to my gas gauge I was at 1/8th of a tank...I filled up and it took nearly 12.5 gallons of fuel. According to the owners manual...the tank size for my vehicle is 13.0 gallons. Needless to say I got very concerned that my gaugue was not working poperly.

I took my car to my local Honda dealer (I know most of the techs there) and they check the guage and sender only to find no problems. They were also at a loss as to where they extra gas went.

As I was leaving an older tech informed me that sometimes you can fill a tank in such a way that it complete fills all the way to the top (usally this does not happen because of air trapped in the tank...acording to what he said) and also fuel can be held in the filler neck hose (sometimes up to 1 gallon extra if you can belive that). He sugested just letting it fill up till the auto shut off activates and stop filling there.

Sure enough...my next fill up at 1/8th of a tank only took 10 gallons (but i got nearly 360 miles out of that tank...wish that worked all the time like that). So I have been watching my gauage very intently lately. Also the tech sugguested that I watch my trip odometer as well...If you are used to getting 300 miles between fill ups...then fill-up every 300 miles or there about just in case there is a intermittet problem with your guage. Its what I am doing.