Bad fuel gauge already?

I have a 2011 Aveo5. It has less than 700 miles on it, and I have noticed that the fuel gauge is off. When I bought the car, I made several highway trips back and forth and at roughly 220mi it was at 1/4th a tank. Fill up was 6.7 gallons. Then I drove some highway and mostly in the city and I was at roughly 301mi at 1/4th a tank and it took 8.2 gallons to fill. This time, I was at 165.3 and when it clicked, it clicked at 6.1 gallons like it was full but then when I got in the gauge was about 1/8th from full and driving home didnt push it back up. My driving is not that different and I was curious if large fluxuations is normal or has people been having issues with the gauges in this car.

The fuel gauge in my car does that as well, It always clicks off at the pump, and then i start it up and it doesnt even read full... Sometimes when starting my car my fuel gauge wont work at all when it has plenty of gas it just sits at E and doesnt move until i restart the car.

mine hasnt shown full since i bottomed out the gas tank on a sewer cover.. it only goes up to 7/8s of a tank.

Yes the gauge fluxuates a lot. It is varies with voltage and the alternator on the aveo ouput varies quite a bit in the rpm range. Rest assured, when the light comes on, you will have a couple litres more than what the manual tells you should have.