My wife has a '07 Honda CR-V with a 2.4L at 9.5:1 compression. Just for fun I put 89 in it about a week ago after the good results I got in my car. The tank is half way down, she's been doing nothing but the normal commute and the gauge reads 23.something MPG. She normally gets like 19 or 20! (She's a total lead foot and only a 5 mile commute to work)
Maybe premium 93 will yield something in our 10.5:1 2.0L? I'll test that next after this third tank of 89.