Ummm, let's see...
Basically, the following units (you may already have the idea ) may contribute to your 750 gas guzzling habit:
- Air filter
- MAF
- Fuel filter
- Fuel pump & injectors
- Coils & Spark plugs
- O2 sensor
- DME & Chip

Well, I would suggest you to replace your V12 w/ a V8. So, mathematically, it would save you at least 1/3 of the gas consumption...

Otherwise, pls buy a gas station (so you will, at least, get a gas at "wholesale" price to feed your V12 monster)...