Welcome to the forum, Jasen.
You've probably seen the other Astro work van thread going on here recently (
http://ecomodder.com/forum/showthrea...sel-26437.html )
The thing about thirsty vehicles: even if your mods and/or improvement in technique might not look numerically impressive (eg. ~20 mpg), small improvements in MPG at that end of the scale represent relatively big savings in fuel & money burned.
So I take it your XR3 will be an additional commuter/trip vehicle? You don't have anything else in that role right now - just the van?