Around 28Mpg for me, but just for fun, Mallory Park I used 3 full tanks of fuel and averaged 6.4MPG 
66 Nitrous Blue, Sync 3, lux pack, black forged alloys, Nitrous callipers. Custom eTune, short shift, Miltech back and sport cat, revo roll restrictor, RamAir induction, airtec intercooler, uprated recirc and SSC ???