I have an 05 tc with 202k miles and I'm getting about 21mpg all together. My daily commute is about 85% highway at 70mph-80mph but even at that speed I've seen people still getting about 26mpg-28mpg. I've even see people say they get up in the 30s and even low 40s mpg. I just got an oil change about a week ago and my tires are at about 35psi last I checked. What am I doing wrong?