2001 Gmc sierra c3 gas mileage Read Also: 2001 Gmc sierra v8 gas mileage 2001 Gmc sierra 4.8 gas mileage 2001 Gmc sierra 2500 sle gas mileage 2001 Gmc sierra gas mileage 2001 Gmc sierra 2500hd gas mileage 2001 Gmc sierra 2500 gas mileage