It's not weird at all, you are probably using the California blend of fuel. It really does kill your gas mileage. The last time I drove to MOAB I got horrible mileage going compared to coming back. On the way out I had to fuel 3 times and only stopped twice on the way home. In fact I last fueled in George on the way home driving all the way to Santa Clarita vs. fueling futher inland east of L.A. on the way out.
