Air filters - think about it. More air supposedly means more performance. More performance = less mpg.

Keep the stock air filter. Replacing it will maybe give you slightly better performance, but your mpg will drop.

I have kept detailed records of my mpg before and after upgrades. I was getting 16mpg stock. After the cat-back, I went up 3 mpg to 19mpg.

Once I replaced the stock air filter with the custom chrome intake and the cone filter, my performance increased (no dynos, just the feel), but my mpg went down to 17.5...

These are real world numbers based on the VX.

To sum up:

Get the PV Muffler (replace the tip to tone down the sound)
Use synthetic oil - Walmart is the best price ($30)
Air up your tires to 40 psi.
Do not use the Power button - this will increase performance, but will decrease mpg (and no, this will not ruin the transmission - where do they find these sales people?)
Do not mash the accelerator pedal to the floor
If you see that you will need to slow down, take your foot off the accelerator and coast as long as possible.

If you want even better gas mileage, replace your engine with the new direct injection engine for the Axiom.

Brent
www.xanderstudios.com