After hearing about valve seat recession, I figured I should get my valves checked (2010 Fit Sport, 120K miles, 90% freeway driving). It turned out they didn't close completely. After the adjustment, I gained about 2 MPG!

 

Nice! I noticed about the same. It's always worth checking your valves.

 

My mechanic suggested a valve adjustment at 100k, so it will be a while since I'm at 50k at 7 years.

 

Well, there's the opposite problem: valve seat recession. Might be worth a check anyway.