Whats wrong with my car's gas meter? help?

The gas gauge on your car is connected to a device on a rod in your gas tank that floats on the top of the liquid gas. When you go around a turn all of the gas shifts from level across the tank to just one side so the level of the liquid under the float isnt as high. Normally the float would spring right back up once the liquid levels out but it sounds like yours might be a little sticky and it takes a bit for it to reach the surface again. Usually the only way to fix this is to pull the gas tank down and replace the float mechanism. Doing that is not something that is quick, and could be relatively expensive depending on the make and model.

Try keeping a full tank of gas in your car for a while, once it gets to 3/4 full just fill it back up. Sometimes this can fix it, sometimes not. Otherwise just keep driving it unless it gets worse.

Those things are never accurate, and never will be so long as they're based on a simple float mechanism. The only time you need to care is when it's down below 1/4 or so, at which time you should refuel.