I'm new to owning a Tahoe, always had a truck. Mine is a 2003 LS with the 5.3 4x4 with 3.73 gears. I've had a truck similar to this but a year older and at 75-80 mph the rpms were around 2000. This Tahoe is around 2300 rpms at 70 mph. At all speeds it seems to run higher rpms than my truck ever did and I'm getting worse gas milage. Is this normal or is there something wrong?