In the four weeks ended Jan. 18, the U.S. imported less oil than we've imported in any period since the year 2000, a level we haven't seen consistently since 1996. It's a product of increased oil drilling across the U.S., and there's a demand aspect as well. Even as the economy has improved over the past three years, the amount of oil supplied to U.S. consumers has fallen.

Over the next decade, it's possible that increased drilling, efficiency, and alternatives could render us almost import-free in the oil market. It's not as crazy as it once appeared.

Efficiency becomes reality Oil drilling gets a lot of the credit for the declining imports, but declining demand should get equal play. According to the U.S. Energy Information Administration, petroleum product supplied in the first 11 months of 2012 averaged 18.639 million barrels per day, 10.4% lower than 2005. Part of this drop is due to the recession that we're still recovering from, but efficiency is playing a bigger role than many people think.

Usage has dropped since 2010 despite growing GDP, and fuel efficiency standards are playing a role. The Obama administration passed a new CAFE standard of 54.5 mpg for auto manufacturers that takes effect in 2025. This is driving long-term planning, but the reason for better efficiency may be closer to the pump.

US Oil Consumption data by YCharts.

A decade ago, you could fill your average tank with a $20 bill. Today, the price has about doubled. That has hit sales of trucks and SUVs, forcing manufacturers to put a premium on fuel efficiency. Ford Motor Company (NYSE:F) can't stop talking about its Eco-Boost engines, and its homepage has the headline "MPG Savvy" as I write. Efficiency is clearly selling.

Economics are also behind the growth of natural gas vehicles and the growing electric vehicle boom. Westport Innovations Inc. (USA) (NASDAQ:WPRT) is working on the technology to make a transition to natural gas, while Clean Energy Fuels Corp. (NASDAQ:CLNE) is building the fueling infrastructure. As the technology improves and infrastructure expands, this will continue to put downward pressure on oil demands.

Supply side Shale drilling has clearly given the U.S. a new oil supply source, but it's interesting to see how efficient drillers are becoming here as well. Baker Hughes Incorporated (NYSE:BHI) has reported a big decline in contracted rigs in the U.S. over the past six months, and one of the reasons is the efficiency of drillers. The following chart shows the decline in U.S. rotary rigs but also reveals a sharp increase in production over the past year.

US Rotary Rigs data by YCharts.

Pad drilling, mobile drilling units, and drilling efficiency have allowed the industry to keep drilling high while reducing rig count. The efficiency and decline in drilling rigs are hitting the results of oil services companies as well. Halliburton Company (NYSE:HAL) , one of the drivers of shale drilling, reported a 5% decline in revenue sequentially, and operating income fell 22%.