I'm running an inline 6, so that helps, and it's pretty much the way it was out of the factory. Put an MSD coil and K&N filter on it. I've cleaned up the engine pretty well so the heat dissapates better, and pretty much flushed the whole system (seafoam in booster, motor flush, etc.). Next I've gotta get better wires, regap my plugs, bump the timing, and clean out the injectors. Hopefully that will help some too.
I filled up again the other day, and this time it was down to about 16 1/2, but that was with about half the miles in stop and go traffic and I wasn't being nice to that little pedal on the right.
brad