32 for Boston area seems pretty good to me and I used to live in MA so I have experience. lol Stop and go is what kills mpg's on the Civic. If I'm in a lot of stop and go 32-34 is what I get.
You can use a site like fuelly.com to keep track of everything.
Some report the i-mid to be pretty much dead on while others have a 1-3 mpg difference. My first few tanks were off by a good 3, but after a few tanks it evened out and now its not even off by 1.
I have gone through four tanks of fuel and have "done the math" on all of the tanks. The results are within .5 of a MPG of what the car is telling me. I was surprised it was so accurate. But I do wish I could say I was over 30 MPG. I average about 27. (manual transmission in EX coupe)