Ouch, that's more fuel I believe than the car can actually burn, even a 12 cyl...gotta have a hole in gas tank!

I hope you were truly exaggerating about your fuel mileage.

 

Must have huge plumes of smoke behind you to run that rich. Check for leaks.

 

If you're gas tank is leaking, you would probably see it when you're parked. It's probably a leak in your fuel lines somewhere. Check the connections at the fuel filter to start.
I guess my 12mpg could be worse, eh?

 

12 mpg would be normal for a v12. I read it as a gallon a mile.

 

Ummmm as Ken said, Look for leaking at fuel lines, especially up at engine. Horror stories could be told of V12's catching fire.