I already have a 99 Regal GS . SC motors like hi-octange and lots of it. The Regal runs great, cmfotable and fast too expensive to fill. My 90 gets way better mpg'*.
Besides i also have a lifted 92 Jeep Cherokee with a 32 gal tank. It gets pretty good on the hywy. 20-22 if you dont fill up the tank. Normally i put about 20 gal in it unless i'm going really far and get the gas cheap. It has a 2000 mtr swapped in just recently.
Lots of mostly factory upgrases including rear disc brakes. There are even a couple jeeps or more running the Camaro/firebird 3.8 and any other motor you can think of.