My gas gauge will only read like 3/4 full even though the tank is totally full, and it appears that the gauge is correct in actual gas used. You know, drive x amount of miles and the needle drops correspondingly. What's up with that? Is it a sending unit problem, a grounding problem, or what ? Kind of nice to know exactly how much gas you do have in your gas tank, esp. when the sixpack is sucking it down like there's no tomorrow.