We continued driving on the very nice Puebla cuota (toll road) and enjoyed the scenery. We passed a Pemex gas station on the other side of the highway and there was not a nearby retorno (turn around). We had a bit more than a quarter of a tank of gas and were sure there would be another soon. We kept driving and driving on what seemed like a never ending highway and around every bend we kept looking for a gas station. Nothing. Beginning to get a bit worried ( we had not once seen one of the 'Green Angel' trucks that are supposed to be everywhere to assist stranded motorists), I watched the gauge move downward to a little less than a quarter tank. Now I was really concerned. We had already turned off the A/C to conserve gas, but the gas-guzzling Ford E-350 van didn't seem to notice. Every few miles there were pull-overs for agua (water for overheated engines I suppose), but no gas. Just as the gauge showed about 1/8 of a tank, dangerously close to empty, in the distance Alan spotted one of the ubiquitous Pemex signs.
Relieved, we stopped, walked the dogs, and vowed to never let the tank go below half.