OK ? I?ve got a mystery with a 2003 Honda Civic LX ? I hit a piece a metal on the hwy and it punctured a hole in the gas tank (this is a story in itself) - anyway Honda replaced the gas tank with a used tank supposedly specific for this yr and model Honda ? after we got the car back it registered a little less than 1/4 of tank. When we filled up it took 14.4 US gals ? owners manual says capacity is 13.2 US gals ? OK that?s odd. Then we drove ~120 miles and the gauge still registered full. When I went to fill up, since we were heading out on along trip, and I couldn?t put more than 3/4 gal in and I could see gas in the filler tube. The next tank seemed fine on the gas gauge and during fill up. Any theory?s as to why this occurred?
Also I noticed that the flap in the gas filler tube is no longer there ? I believe this is a safety feature and was going to get Honda to replace it. Comments?
I am not absolutely certain, but I think the capacity of a gas tank is what it takes to fill it up after the fuel pump will no longer take up fuel. There should be a little left as the pump usually does not take gas from the bottom of the tank. When the replacement tank was initially filled you had to add the amount that will be left when it is “empty” again. Other things could cause this also, such as the station shorting you on a gallon, topping off the tank, filling up the filler tube (If the flap is missing that may cause more gas to go into the tank/tube than is safe, so get it replaced.)
First, if you tend to top off the tank, don’t do that. It can damage the system. The tank should be full the first time the pump kicks off. Putting too much fuel in can damage the vent system causing it to fail resulting in more pollution and difficulty in filling the tank. It is not a cheap fix.
I would not be surprised if more than one tank design may have been used in any one year. Mid year changes are not at all unusual. Likely they are interchangeable, but could have slightly different capacities. My 2002.5 car has several changes where were standard from the start on the 2003 model.