[Big Van]

I accidentally posted this in the regular forum, not realizing there was an "introductions" section... Anyway, here it is, appropriately re-posted:

This is my first post, and I'd like to start off by saying that this community is really inspiring: regular folks stepping up and doing what needs to be done when industry and government fail to do so.

That said, I have a big question for you all: Is there anything that can be done for my poor gas-guzzling 15-passenger van? (I know, the real answer is to melt it down and make four or five normal sized cars from the resulting material, or even better, a fleet of bicycles. Sadly, I'm in a touring band, so the van is a somewhat-necessary evil.)

Currently this monster gets about 15 mpg when driven conscientiously. I'm wondering if a belly pan, wheel skirts, different tires, etc. would make enough of a difference to even be worth the effort. Are there any appreciable gains to be made on a vehicle that weighs five thousand pounds and is shaped like a cinder block? Any help would be greatly appreciated!