trying to figure out if there is something wrong with my truck or if I am just being paranoid? I have an 04 silverado 5.3 ext cab, I filled it up the other day and it got to 200 miles on the trip meter right at half a tank, which is normal, but between half and quarter it only got 50 miles, this is the way it has been for a while now, no SES light or anything seems to run good no gas smell, just wondering what I can do or if this a normal thing I am tired of going like 5 days on a half tank then 2 for the last half. Thanks