The last time we visited President Barack Obama's promise to reduce oil consumption, he'd been pushing a number of initiatives meant to lower fuel consumption and improve energy efficiency.

The approval of new fuel efficiency standards for cars and light trucks has advanced this promise further.

The new rules, which were proposed in May 2009 and put on the books April 1, 2010, will require cars and trucks manufactured starting in 2012 to have an average fuel economy of 35.5 miles per gallon by 2016.

According to the Obama administration, the mandate will also save consumers money and reduce oil consumption.

Here are the specifics:

Better fuel efficiency will save about 1.8 billion barrels of oil over the lifetime of the vehicles regulated under the new law. On the campaign trail, Obama specifically said that he wanted to save about 2.5 million barrels of oil daily. Quick math tells us that, on average, the new rules will save that much per day over a period of about two years. The trouble here is that Obama did not give a time frame on this part of his promise; he did not specify how long he wanted to save 2.5 million barrels of oil per day.

The Obama administration also says that the rules will take the equivalent of 50 million cars and light trucks off the road in 2030, which was also part of Obama's original promise.

Obama promised to save consumers $50 billion at the gas pump. This part of his promise is trickier to measure. Officials say that "the rules could potentially save the average buyer of a 2016 model year car $3,000 over the life of the vehicle." So, that means that upwards of 17 million people would have to buy new cars in 2016, and at best save $3,000 over the lifetime of their new cars to meet Obama's $50 billion goal.

Another recent announcement from the Obama administration could increase the amount of oil produced domestically even further. On March 31, 2010, Obama said that he would be opening up new areas to drilling, though critics say that the amount of oil new drilling will produce won't be nearly enough to satisfy American demand for fossil fuels for that long.

So, Obama has made some important headway on this promise. But we're still not sure how these new rules will impact how much people pay for gas. Furthermore, some of Obama's other initiatives to improve energy efficiency and reduce reliance on fossil fuels aren't finished yet. As a result, we'll be leaving this promise at In the Works for now.