You’re cruising down the highway, windows down, belting out your favorite Taylor Swift song. A sign whizzes past, and you see a number which stands triumphantly above all other numbers: the sweet, sweet price of $2.99. That could be the cost of an iced tea at Cub or a hat at Goodwill, but instead it is the monetary value of a gallon of gas. After growing up with the idea that gas prices will only go up, charges this low seem like an urban legend. But here we are, the newest drivers in the United States, and gas prices are the lowest they’ve been in four years.

Why? First and foremost is the rather obvious fact that gas prices track closely with crude oil. Crude oil is currently down 25% since June. So let’s look at three central reasons that national gas prices have fallen to $3/gallon.

First of all, The US is currently producing an oil market supply gut. Soon, the US could be pumping more out of the ground than Saudi Arabia. As the amount of crude oil in the market increases, the prices decrease.

The second reason is a decrease in demand. Thanks to the popularization of green technology, the developing world has begun the transition into renewable energy. But it’s not just us: other countries have seen a remarkable decrease in the need for gasoline. If you ever thought Europe was too far away to have an effect on our Minnetonka bubble, you’re wrong. The German economy is becoming sluggish, which means that fewer large factories and corporations require shipping fuels. When you couple this chain reaction with the rising amount of oil in the market, it amplifies the effect.

Third, we can thank OPEC for the change that still jingles in our wallets when we walk away from the pumps. OPEC (Organization of Petroleum Exporting Countries) is a coalition of nations that control about a third of the world’s oil supply. Usually when the supply of crude oil spikes, OPEC reduces their production to counterbalance the decreasing supply. This drives the price back up, and drives the corners of our mouths down. Like Sarah Palin before it, Saudi Arabia spent last summer “going rogue.” They cut their oil prices, causing a rift with OPEC. As of yet, the two entities have been unable to pull together to cut off the oil supply.

What does this mean for your weekly gas budget? Will you still have the cash to buy Taylor’s new album? Will you ever accumulate the dough to buy a Ferrari? Will you ever go to college? WHO KNOWS! All we know is that companies rarely allow the price per barrel of oil to plummet below $80, which is right around the current level. If history repeats itself, we could see oil companies reduce production, and the price of gas would yet again begin to rise. So next time you find yourself at the local Holiday, thank OPEC for supply and demand—at least, for now.