I have a 2007 Accord EX-L V6 with only 300 miles on it. It comes standard with the Michelin 17 215 50 series MXM's. Seem to be certainly biased toward handling which I like, but I find the ride HARD. I wondered if putting on 55 series rubber might help, but I received conflicting advice: the negative kind said the cars's computerized systmes are all calibrated for those size tires, and adding diameter will mess up the VSA, tranny, ABS, speedometer, odometer, etc. One dedicated Honda Fix-It palce said it was okay. So, now I'm confused and looking for the definitive word. Anybody ever done this? If so, what kind of tires, and waht was the result?  

you should be fine going with a little more rubber, and this is not the first time that i have heard this about the 2002-2007 accord. You do understand that with the larger tire your handling with be reduced and the feel of the road will also be reduced. Right now im running a 215-55-15 on my 02 SI and it came with 195-65-15's.

now Your vehical stability assist should not be affect nor should the tranny, but you speedometer may be off by a couple mph due to more rotating mass but i would say a couple mph at most.

hope this helps