I just a term paper on a similar topic, more related to aviation fuel, but my research covered the same stuff. It's all about the scarcity of oil, I don't remember the figures exactly, but consumption is almost equal to production. Say they(all prouducers) produce 1 million barrels a day, we're(the world) are using 900,000. And the wells aren't filling themselves back up. Also, the refineries, are maxed out, they're redlined as far as pruduction, sure they can suck more oil out, but they need the tooling to do it, and, as found in my research, the last major refinery was consturcted inthe 70's, not designed to handle today's demands. To top it off, the geoligists aren't having alot of luck finding new fields. The 70's gas scare was OPEC f'ing with us, as is not the case now, they're maxed out as well. Supply and demand.
If you look at Europe, we got it good. When I lived in Germany, I filled my Focus up at Ramstein Airbase's fuel station (US prices for military members) cost me ~15 bucks. Drove down to Paris, had to fill up on the way back cost 44 euros, whicha t the time was about 60 bucks, this was a few years ago, when gas wasn't so high. Anyway, try a Google search, with fuel/oil price, lot of info out there on the subject.
May your tank never run dry...good luck
Brian