J7erry

I have a CAI, but no tune yet. I noticed better performance when I run 91 octane (highest we have around me). I don't downshift as much going up hills and start off feels better. As far as mileage, I noticed a negligible difference with 91 vs 87

WORKISSLOW

I noticed a pretty clear difference with both power and fuel economy after the tune on 91 octane, I only noticed a modest difference between 87 and 91 before the tune.