Excessive Fuel Consumption - '93 Wrangler

I just removed the 20 gallon fuel tank to replace the sending unit gasket. Got everything back together but now notice what appears to be excessive fuel consultion. Perhaps its the fuel gauge? This damn fuel gauge never did record accurately - show zero when I know thare are at least 4 fallons in the tank! Doesn't appear to be any fuel leakage anymore. Could there be an issue with tank pressurization? Thoughts?

Fill the tank up, drive like 150 miles (or a long distance without running out of fuel), fill up the tank after that. Then divide miles traveled by gallons of gas used ... that can at least give a close estimate to what you are getting for mileage.