Gas is cheaper than bottled water by a lot. 1 gal=128 floz. 1 bottle=16 floz. 1 gal=8 bottles. If a bottle of water is $1, a gallon would be $8 as opposed to gasoline's $2.8-4/gal.
The chances are fairly slim that your gasoline contains many actual former dinosaurs. Most oil came from marine plankton and algae. http://what-if.xkcd.com/101/
drinking gasoline will save you money in the long and short run.