My Accord V6 Coupe has a few mods. Beside the custom cat-back I have an AEM short ram intake etc. I did't loose the 22 city and 32 highway and gained some hp & touque..
With my new FIT I have gone to some forums & find out that there may be hp & torque but a significant loss in fuel efficiency with a short air ram. Though currently no company (AEM or K&N at least) makes any kind of short cool air ram system. AEM only offers the intake & filter for the MT. I have an AT. K&N said they will possibly offer a short ram intake some time in Aug or Sept. Is the fuel efficiency loss for real?
Though I have also lowered my Accord I probably won't do this with the FIT. I would like to put in a rear upper sway bar but do not want to mess with opening holes in the roof & would really like a lower one that can be made to set aside w/o using a wrench on the mini-towers in the rear. Kind of like the kind that will break apart in the middle and pull to each side to keep from losing the space to haul and still be stiff enough to do the job...
My FIT attracts attention (so far no babes) all of the time. I even had a guy filling up his new Chevy truck hauling a new large boat want to see the gas milage as well as sit in it!

 

I have loss, but is that you start to really like how it responds and sound. You end runing faster and redlining just to have fun and voalį, mpg loss. It is your foot who decides the mpg. Is like with a prius or so, if you dont re-educate your driving style, you'll consume gas, and a lot.