One other thing that I didn't see mentioned above. When you fuel up be sure that you DO NOT top off. Once the pump clicks off, resist the urge to give it one last squeeze, this will help to ensure that you're filling the tank to the same level every time and will improve your MPG accuracy from tank to tank over the long haul.
Also, good luck with the EX! I just got a 2010 LX and using much of what was cited above, I got 32 MPG on my first fill up.
dslater, this does not work the same for every vehicle.
My beretta for example will NOT fill consistently with this method, whereas the caravan is usually pretty close.
I always squeeze them up till they are full. My beretta often can hold a gallon or more past the pop point. Its never the same either. The van however is usually within 50 cents or so of being full.
How do I know if its full? When I'm trickling it in, and it starts to pop really easy, plus I can hear the filling sound change a bit as it fills. This takes practice, but if you use common sense, it works really well. I usually round my fillups within 50 cents. (example 10.50 or 11.00)
This can also be affected by temperature, and by different pumps/stations. Not all of them pop the same way. One station I go to, if filling the van, it will pop it constantly, even though it isn't full.
I have issues with people who post on here and state what you did, as it is not the same for everyone. In my experience it actually caused me more inconsistency than filling it to the neck every time as I do.
My recommendation, is to find what fills it properly, and always fill it the same way. Whether that be by stopping when the particular pump you are at *thinks* you are full, or filling it to where you know its full.
I have even been known to shake the car a bit to make sure it was completely full, dislodge any air bubbles in the tank. But that is overkill for most. lol