Thinking about this some more the retail price is not a fair comparison. That's because there's significant cost externalization in the petroleum world. In addition to the pump price, we pay the cost of air pollution, water pollution, soil pollution, aggravation of lung problems due to smog (which in turn gets us into aesthetic costs), not to mention various tax breaks such as the (27%?) oil depletion allowance (to enable the petro companies to find alternate energy sources--still waiting on that). And, if you are really cynical, you can throw the cost of going to war over oil on the pile as well. As far as water goes, I can't think of many additional costs society has to pay in the bottled water arena except for the bottle recycling/disposal cost. So, gas definitely costs more. Just my opinion.