Eco-friendly cars are gaining in popularity, but not all efficient vehicles are created equal. Your choice of fuel matters if you’re concerned about emissions and fossil fuel use.

Alternative fuel vehicle options include biodiesel, hybrid cars combining electric and fuel modalities, and fully electric options. Each comes with its unique environmental impacts. For drivers who want to do the least harm, these three considerations can determine what fuel-efficient vehicle is the right pick.

Hybrids: Popularity and Convenience

The most popular energy-efficient options available are hybrid vehicles, such as the Toyota Prius and Chevrolet Volt. These cars were among the first mass-produced eco-friendly vehicles. They are relatively affordable and easy to maintain, as they use a traditional gas engine to back up the electric operation. And because most can run exclusively on electrical power for short distances, hybrids burn less fuel. How much less depends on driving conditions, battery charge, and other factors like driving style.

Of course, the counterpoint to hybrid vehicles is they still use fossil fuels — but that may change soon. Nissan is developing a new biofuel program that will burn a 10 percent ethanol blend to offset carbon dioxide emissions.

Biodiesel: All Alternative Fuel

For many years, biodiesel was considered the cutting-edge solution to fossil fuels. Now, under more heavily regulated conditions, car companies have been developing engines that run on soybean-based or corn-based fuel blends to reduce emissions. Known as B100, pure biofuel has been found to reduce carbon emissions by 74 percent compared to traditional petroleum fuels. That kind of reduction is transformative.

Depending on blend percentages, many cars can run on biodiesel, but not very many can run on B100 yet. However, most cars can run on B20, a 20 percent biodiesel to 80 percent traditional diesel blend. For anyone interested in making more eco-friendly driving decisions and increasing vehicle efficiency, seeking a local B20 blend supplier is a good start.

Electricity: Understanding the Energy Source

As for their energy efficiency, concerned drivers need to ask an important question about electric vehicles: “Where does the electricity come from?” Electricity doesn’t just appear, and a surprising number of these “clean” vehicles get their charge via coal-burning power plants. Just because drivers don’t see the source of the energy doesn’t mean electric vehicles are necessarily good for the environment.

The Final Word

When it comes to green vehicles, electric vehicles may not be all they’re hyped up to be. However, both hybrid and biodiesel-powered cars reduce emissions significantly. They’re generally affordable, have a significant driving range, and don’t require extensive infrastructural support. Continued support for hybrid and biodiesel vehicles may be the best solution for our fossil fuel addiction.

By Anna Johansson

Anna is a freelance writer, researcher and business consultant. A columnist for Entrepreneur.com, HuffingtonPost.com and more, Anna loves enjoying the great outdoors with her family. Follow her on Twitter and LinkedIn.