MPG is never going to be your friend in a VX...better get used to it, or I guess maybe get a civic like the others said...

There's many threads and posts about MPG, many before you have asked, and I'm sure many after you will too. The "search" function will be your best friend on all matters. Luckily, this forum is very active and has numerous knowledgeable owners that have documented and answered a ton of questions here and make it a fantastic resource.
Here's a few I found. Read Read Read.

http://vehicross.info/forums/showthr...ht=gas+mileage

http://vehicross.info/forums/showthr...ht=gas+mileage
Specifically post #9

http://vehicross.info/forums/showthr...ht=gas+mileage
Specifically read post #11, Eric gives some good general tips.