I get between 22 and 24 normally on my NA. 28-30 on a trip, the winter blend of gas is poorer quality so it's more like the 22 in the daily commute. in summer it goes back to between 24-almost 26. I almost always use the 89 and runs like a champ. BTW, I really like those yellow calipers on the Aero Blue Mike. Look really sharp.