The expected drop in gas prices is due to the convergence of several factors:

  • Iran's oil: Following Tuesday's historic nuclear agreement, Iran's oil will be allowed to flow into countries where it was previously blocked due to sanctions.
  • Iranian production will increase: Even more oil will flow from Iran next year, as Iran upgrades its infrastructure to meet new demand.
  • Supply is up: Iran's oil will add to what is already considered a glut of oil on the world market.
  • Demand is down: Blame it on economic problems in Europe and China, is also putting downward pressure on gas prices.

Gas prices vary widely, of course. While the national average is $2.78 a gallon, the average in Los Angeles is 4.20 a gallon — a big jump from last week, when it was $3.55. The Southern California market is quirky, analysts say.

>> Check the average gas price in your city and state here.