So, what exactly is this EPA SmartWay certification program?
EPA SmartWay Certification is a designation a vehicle receives from the Environmental Protection Agency, an agency that is part of the federal government. An EPA SmartWay designation means that the vehicle has met standards for air pollution and greenhouse gas emissions, as well as fuel economy. As the EPA states it on their website, "SmartWay helps you identify cleaner, more fuel efficient transportations options."
The EPA has designed a chart to assist consumers in evaluating fuel efficiency and emissions on vehicles currently being sold in the U.S. On the chart are two separate categories used for emissions evaluation. The one on the left is referred to as the Greenhouse Gas Score. On the right is the Air Pollution Score. In order to qualify as a SmartWay Vehicle, the vehicle must have a combined score of 13, with a score of six or higher in both categories.
CO2 (carbon dioxide) is considered a greenhouse gas, which is believed to contribute to global warming. It is measured in pounds released per mile driven. In addition, this side of the chart shows fuel economy ratings for each score level. Note that the EPA uses their emissions testing data to calculate the fuel economy of vehicles as well. (See "How are vehicles tested for emissions" question below.)
On the Air Pollution side of the chart, the EPA uses abbreviated terms to refer to designations given to vehicles that are more efficient than others. Here is a basic breakdown of those terms and examples of vehicles the EPA has associated with these terms: ZEV-Zero Emission Vehicle; Toyota RAV4 EV/Electric Vehicle. SULEV-Super Low Emission Vehicle; Toyota Prius/Hybrid. ULEV-Ultra Low Emission Vehicle; Honda Civic HX/Manual. LEV-Low Emission Vehicle; Chevrolet Prism/Manual.
Below are some of the most frequently asked question regarding the SmartWay designation. These questions and answers come directly from the EPA website.
How do I find the greenest vehicle possible?
We have identified the lowest emitting and most fuel efficient vehicles with a "SmartWay" designation. In addition, the best of those are identified as "SmartWay Elite."
What do the Air Pollution Scores mean?
Each score reflects one set of emissions standards for four different air pollutants: oxides of nitrogen (NOx), carbon monoxide (CO), volatile organic compounds (VOC), and particulate matter (PM). The manufacturer is liable for ensuring that a properly maintained vehicle will emit no more than the given limit of each of these pollutants for each mile that the vehicle is driven. The Air Pollution Score, which is a surrogate for the actual emission standards, is on a scale of 0-10, with 10 being the cleanest or best score.
How are vehicles tested for emissions?
Before a vehicle manufacturer can offer a new vehicle for sale, EPA requires that various laboratory emission tests be conducted on a vehicle representative of the vehicles that will be sold to car buyers to ensure that the vehicles will meet the emission standards. The tests are designed to simulate a wide variety of actual on-road operating conditions (such as highway driving and city driving). The data from these tests are also used to calculate city and highway fuel economy (mpg) values which appear on the window stickers of new vehicles.
Why do we need scores at all? Don't all vehicles meet the requirements?
All vehicles sold in the US must comply with federal emission standards. However, the standards are packaged in various "bins" that manufacturers can choose from, meaning that in a given model year, some vehicles will be cleaner than others. By means of the Air Pollution Score the Green Vehicle Guide shows you which vehicles are the cleanest.
What are EPA's emission standards and why are they important?
EPA's newest standards, called "Tier 2," provide auto manufacturers with an array of emissions standards they can choose for any particular vehicle model, as long as all the new vehicles they sell in a given model year fall below a required average (bin 5). The emission standards are in effect from the time the vehicle is produced until the vehicle reaches the legally-defined end of its useful life (10 years or 120,000 miles for most cars) - manufacturers are responsible for designing vehicles that will pollute no more than the emission standard limits.