The US Environmental Protection Agency (EPA) has reported that car companies are certainly catching on to the green revolution, consistently creating cars with significantly lowered emissions and improved gas mileage compared to past models.

That's at least according to the EPA's annual "Light-Duty Automotive Technology, Carbon Dioxide Emissions, and Fuel Economy Trends," which has followed car and sport utility vehicle model design since 1975.

According to the report, overall fuel economy of civilian vehicles sold in the United States has increased in eight of the last nine years, and the average carbon dioxide emission is now at a record low of 369 grams per mile for cars boasting the model year 2013.

"Today's announcement points to the greatness of American ingenuity and the strength of our auto industry. Our report shows that today's vehicles are saving Americans money at the pump while emitting fewer greenhouse gases. We are thrilled to see that manufacturers continue to innovate and are bringing technologies to improve fuel economy online even faster than anticipated," EPA Administrator Gina McCarthy said in a statement on Wednesday. "Consumers now have many more choices when shopping for vehicles with higher fuel economy and lower emissions compared to just five years ago. These choices reflect both a more diverse range of technology packages on conventional gasoline vehicles as well as more advanced technology and alternative-fueled vehicles."

And these changes may also be in-part due to the fact that the EPA and the Department of Transportation recently implemented new vehicle standards that are projected to double fuel economy by 2025 and cut vehicle greenhouse gas emissions in half.

Recent changes announced back in March will also will reduce gasoline sulfur levels by more than 60 percent - down from 30 to 10 parts per million in 2017, enabling vehicle emission control technologies to perform more efficiently.

"Once fully in place, the standards will help avoid up to 2,000 premature deaths per year and 50,000 cases of respiratory ailments in children," the administration said.

Still, when it comes to air quality and greenhouse gas emissions, experts remains less concerned about automotive emissions, and more about power plants, for the United States was found to be home of some of the world's "dirtiest" power plants.