I don't know if other people are having this problem but I am losing roughly 1.5 gallons per trip. I used to get approximately 415-430 miles per trip at 22.5-23 mpg before my empty light went on. Empty light comes on at 2.5 gallons left with a tank capacity of 21 gallons. I am now averaging 380 miles at the same mpg of 22.5-23. If you do the math I am only getting 17 gallons of gas per trip but when I fuel up it takes 18.5 gallons of fuel to refill my tank. I have taken the truck to the chevy service to be looked at and they can't find any leak or any faults in the computer system. I have changed where I went to get fuel thinking maybe I was getting watered down fuel but sadly nothing has changed. Anybody have any bright ideas? I almost want to trade in my truck.

 

Around here they use different gas formulations in Summer and Winter and I get different economy. Ethanol blended fuel also contains less energy.

Make sure the engine is running well. Check air filter, spark plugs etc. Check tire pressure.

 

if you are getting 23mpg the truck is running properly.
https://www.fueleconomy.gov/feg/Find...n=sbs&id=38389