A green vehicle, clean vehicle, eco-friendly vehicle or environmentally friendly vehicle is a road motor vehicle that produces less harmful impacts to the environment than comparable conventional internal combustion engine vehicles running on gasoline or diesel, or one that uses certain alternative fuels.[1] [2] Presently, in some countries the term is used for any vehicle complying or surpassing the more stringent European emission standards (such as Euro6), or California's zero-emissions vehicle standards (such as ZEV, ULEV, SULEV, PZEV), or the low-carbon fuel standards enacted in several countries.[3]
Green vehicles can be powered by alternative fuels and advanced vehicle technologies and include hybrid electric vehicles, plug-in hybrid electric vehicles, battery electric vehicles, compressed-air vehicles, hydrogen and fuel-cell vehicles, neat ethanol vehicles, flexible-fuel vehicles, natural gas vehicles, clean diesel vehicles, and some sources also include vehicles using blends of biodiesel and ethanol fuel or gasohol.[2] [4] In 2021, with an EPA-rated fuel economy of 142 miles per gallon gasoline equivalent (mpg-e) (142mpgus), the 2021 Tesla Model 3 Standard Range Plus RWD became the most efficient EPA-certified vehicle considering all fuels and all years, surpassing the 2020 Tesla Model 3 Standard Range Plus and 2019 Hyundai Ioniq Electric.
Several authors also include conventional motor vehicles with high fuel economy, as they consider that increasing fuel economy is the most cost-effective way to improve energy efficiency and reduce carbon emissions in the transport sector in the short run. As part of their contribution to sustainable transport, these vehicles reduce air pollution and greenhouse gas emissions, and contribute to energy independence by reducing oil imports.[2] [5]
An environmental analysis extends beyond just the operating efficiency and emissions. A life-cycle assessment involves production and post-use considerations. A cradle-to-cradle design is more important than a focus on a single factor such as energy efficiency.
See main article: Energy efficiency in transport. Cars with similar production of energy costs can obtain, during the life of the car (operational phase), large reductions in energy costs through several measures:
| Comparison of several types of green car basic characteristics (Values are overall for vehicles in current production and may differ between types) | ||||||
|---|---|---|---|---|---|---|
| Type of vehicle/ powertrain | Fuel economy (mpg equivalent) | Range | Production cost for given range | Reduction in CO2 compared to conventional | Payback period | |
| Conventional ICE | 10–48 | Long (400–600 mi) | Low | 0% | - | |
| Biodiesel | 18–71 | Long (360–540 mi) | Low | varies depending on biodiesel source[6] | - | |
| All-electric | 54–142 | Shorter (114–259 mi) Luxury models Medium (419–516 mi) | High Very high | varies depending on energy source | - | |
| Hydrogen fuel cell | 80 | Astronomical | ||||
| Hybrid electric | 30–60 | 380 mi[7] | Medium | 5 years | ||
Green vehicles include vehicles types that function fully or partly on alternative energy sources other than fossil fuel or less carbon-intensive than gasoline or diesel.
Another option is the use of alternative fuel composition in conventional fossil fuel-based vehicles, making them function partially on renewable energy sources. Other approaches include personal rapid transit, a public transportation concept that offers automated, on-demand, non-stop transportation on a network of specially built guideways.
See also: Electric vehicle and Plug-in hybrid. Examples of vehicles with reduced petroleum consumption include electric cars, plug-in hybrids and fuel cell-powered hydrogen cars.
Electric cars are typically more efficient than fuel cell-powered vehicles on a Tank-to-wheel basis.[8] They have better fuel economy than conventional internal combustion engine vehicles but are hampered by range or maximum distance attainable before discharging the battery. The electric car batteries are their main cost. They provide a 0%[9] to 99.9% reduction in CO2 emissions compared to an ICE (gasoline, diesel) vehicle, depending on the source of electricity.[10]
See also: Hybrid vehicle. Hybrid cars may be partly fossil fuel (or biofuel) powered and partly electric or hydrogen-powered. Most combine an internal combustion engine with an electric engine, though other variations too exist. The internal combustion engine is often either a gasoline or Diesel engine (in rare cases a Stirling engine may even be used[11]). They are more expensive to purchase but cost redemption is achieved in a period of about 5 years due to better fuel economy.[12] [13]
See also: Compressed-air vehicle and Compressed air car.
Compressed air cars, stirrling-powered vehicles, and Liquid nitrogen vehicles are less polluting than an electrical vehicles, since the vehicle and its components are environment friendly.
Solar car races are held on a regular basis in order to promote green vehicles and other "green technology". These sleek driver-only vehicles can travel long distances at highway speeds using only the electricity generated instantaneously from the sun.
See main article: Biofuel, compressed natural gas and clean diesel.
See also: Volkswagen emissions scandal. A conventional vehicle can become a greener vehicle by mixing in renewable fuels or using less carbon intensive fossil fuel. Typical gasoline-powered cars can tolerate up to 10% ethanol. Brazil manufactured cars that run on neat ethanol, though there were discontinued. Another available option is a flexible-fuel vehicle which allows any blend of gasoline and ethanol, up to 85% in North America and Europe, and up to 100% in Brazil.[14] Another existing option is to convert a conventional gasoline-powered to allow the alternative use of CNG. Pakistan, Argentina, Brazil, Iran, India, Italy, and China have the largest fleets of natural gas vehicles in the world.[15]
Diesel-powered vehicles can often transition completely to biodiesel, though the fuel is a very strong solvent, which can occasionally damage rubber seals in vehicles built before 1994. More commonly, however, biodiesel causes problems simply because it removes all of the built-up residue in an engine, clogging filters, unless care is taken when switching from dirty fossil-fuel derived diesel to bio-diesel. It is very effective at 'de-coking' the diesel engines combustion chambers and keeping them clean. Biodiesel is the lowest emission fuel available for diesel engines. Diesel engines are the most efficient car internal combustion engines. Biodiesel is the only fuel allowed in some North American national parks because spillages will completely bio-degrade within 21 days. Biodiesel and vegetable oil fuelled, diesel engined vehicles have been declared amongst the greenest in the US Tour de Sol competition.
This presents problems, as biofuels can use food resources in order to provide mechanical energy for vehicles. Many experts point to this as a reason for growing food prices, particularly US Bio-ethanol fuel production which has affected maize prices. In order to have a low environmental impact, biofuels should be made only from waste products, or from new sources like algae.
Multiple companies are offering and developing two, three, and four wheel vehicles combining the characteristics of a bicycle with electric motors. US Federal, State and Local laws do not clearly nor consistently classify[16] these vehicles as bicycles, electric bicycles, motorcycles, electric motorcycles, mopeds, Neighborhood Electric Vehicle, motorised quadricycle or as a car. Some laws have limits on top speeds, power of the motors, range, etc. while others do not.[17] [18] [19] [20]
Horse and carriage are just one type of animal propelled vehicle. Once a common form of transportation, they became far less common as cities grew and automobiles took their place. In dense cities, the waste produced by large numbers of transportation animals was a significant health problem. Oftentimes the food is produced for them using diesel powered tractors, and thus there is some environmental impact as a result of their use.
See also: Bicycle sharing system. Human-powered transport includes walking, bicycles, velomobiles, row boats, and other environmentally friendly ways of getting around. In addition to the health benefits of the exercise provided, they are far more environmentally friendly than most other options. The only downside is the speed limitations, and how far one can travel before getting exhausted.
Vehicle emissions contribute to the increasing concentration of gases linked to climate change.[21] In order of significance, the principal greenhouse gases associated with road transport are carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O).[22] Road transport is the third largest source of greenhouse gases emitted in the UK, and accounts for about 27% of total emissions,[23] and 33% in the United States.[24] Of the total greenhouse gas emissions from transport, over 85% are due to CO2 emissions from road vehicles. The transport sector is the fastest growing source of greenhouse gases.[25]
Vehicle pollutants have been linked to human ill health including the incidence of respiratory and cardiopulmonary disease and lung cancer. A 1998 report estimated that up to 24,000 people die prematurely each year in the UK as a direct result of air pollution.[26] According to the World Health Organization, up to 13,000 deaths per year among children (aged 0–4 years) across Europe are directly attributable to outdoor pollution. The organization estimates that if pollution levels were returned to within EU limits, more than 5,000 of these lives could be saved each year.
Hybrid taxi fleet operators in New York have also reported that reduced fuel consumption saves them thousands of dollars per year.[27]
A study by CNW Marketing Research suggested that the extra energy cost of manufacture, shipping, disposal, and the short lives of some of these types of vehicle (particularly gas-electric hybrid vehicles) outweighs any energy savings made by their using less petroleum during their useful lifespan.[28] This type of argument is the long smokestack argument.[29] Critics of the report note that the study prorated all of Toyota's hybrid research-and-development costs across the relatively small number of Priuses on the road, rather than using the incremental cost of building a vehicle; used109000miles for the length of life of a Prius (Toyota offers a 150000miles warranty on the Prius' hybrid components, including the battery), and calculated that a majority of a car's cradle-to-grave energy gets expended during the vehicle's production, not while it is driven.[30] Norwegian Consumer Ombudsman official Bente Øverli stated that "Cars cannot do anything good for the environment except less damage than others." Based on this opinion, Norwegian law severely restricts the use of "greenwashing" to market automobiles, strongly prohibiting advertising a vehicle as being environmentally friendly, with large fines issued to violators.[31] [32] [33] [34]
Some studies try to compare environmental impact of electric and petrol vehicles over complete life cycle, including production, operation, and dismantling. [35] [36] [37] [38] In general, results differ vastly dependent on the region considered, due to difference in energy sources to produce electricity that fuels electric vehicles. When considering only CO2 emissions, it is noted that production of electric cars generate about twice as much emissions as that of internal combustion cars. However, emissions of CO2 during operation are much larger (on average) than during production. For electric cars, emissions caused during operation depend on energy sources used to produce electricity and thus vary a lot geographically. Studies suggest that when taking into account both production and operation, electric cars would cause more emissions in economies where production of electricity is not clean, e.g., it is mostly coal based. For this reason, some studies found that driving electric cars is less environmentally damaging in western US states than in eastern ones, where less electricity is produced using cleaner sources. Similarly, in countries like India, Australia or China, where large portion of electricity is produced by using coal, driving electric vehicles would cause larger environmental damage than driving petrol vehicles. When justifying use of electric cars over petrol cars, these kinds of studies do not provide sufficiently clear results. Environmental impact is calculated based on fuel mix used to produce electricity that powers electric cars. However, when a gas vehicle is replaced by an equivalent electric vehicle, additional power must be installed in electrical grid. This additional capacity would normally not be based on the same ratios of energy sources ("clean" versus fossil fuels) than the current capacity. Only when additional electricity production capacity installed to switch from petrol to electric vehicles would predominantly consist of clean sources, switch to electric vehicles could reduce environmental damage. Another common problem in methodology used in comparative studies is that it only focuses on specific kinds of environmental impact. While some studies focus only on emission of gas pollutants over life cycle or only on greenhouse gas emissions such as CO2, comparison should also account for other environmental impacts such as pollutants released otherwise during production and operation or ingredients that can not be effectively recycled.[39] Examples include use of lighter high performing metals, lithium batteries and more rare metals in electric cars, which all have high environmental impact.
A study that also looked at factors other than energy consumption and carbon emissions has suggested that there is no such thing as an environmentally friendly car.[40]
The use of vehicles with increased fuel efficiency is usually considered positive in the short term but criticism of any hydrocarbon-based personal transport remains. The Jevons paradox suggests that energy efficiency programs are often counter-productive, even increasing energy consumption in the long run.[41] Many environmental researchers believe that sustainable transport may require a move away from hydrocarbon fuels and from our present automobile and highway paradigm.[42] [43]
The European Union is promoting the marketing of greener cars via a combination of binding and non-binding measures.[44] As of April 2010, 15 of the 27 member states of the European Union provide tax incentives for electrically chargeable vehicles and some alternative fuel vehicles, which includes all Western European countries except Italy and Luxembourg, plus the Czech Republic and Romania. The incentives consist of tax reductions and exemptions, as well as of bonus payments for buyers of electric cars, plug-in hybrids, hybrid electric vehicles and natural gas vehicles.[45] [46]
The United States Environmental Protection Agency (EPA) is promoting the marketing of greener cars via the SmartWay program. The SmartWay and SmartWay Elite designation mean that a vehicle is a better environmental performer relative to other vehicles. This US EPA designation is arrived at by taking into account a vehicle's Air Pollution Score and Greenhouse Gas Score. Higher Air Pollution Scores indicate vehicles that emit lower amounts of pollutants that cause smog relative to other vehicles. Higher Greenhouse Gas Scores indicate vehicles that emit lower amounts of carbon dioxide and have improved fuel economy relative to other vehicles.
To earn the SmartWay designation, a vehicle must earn at least a 6 on the Air Pollution Score and at least a 6 on the Greenhouse Gas Score, but have a combined score of at least 13. SmartWay Elite is given to those vehicles that score 9 or better on both the Greenhouse Gas and Air Pollution Scores.
A Green Vehicle Marketing Alliance, in conjunction with the Oak Ridge National Laboratory (ORNL), periodically meets, and coordinates marketing efforts.[47]
Several automobile magazines, motor vehicle specialized publications and environmental groups publish annual rankings or listings of the best green cars of a given year. The following table presents a selection of the annual top pickings.
| Selected annual rankings of green cars | ||||||
|---|---|---|---|---|---|---|
| Vehicle | Year model | Type of vehicle/fuel | EPA Combined mileage (mpg) | EPA City mileage (mpg) | EPA Highway mileage (mpg) | |
| Most efficient EPA-certified vehicles based on combined MPG rating[48] [49] [50] [51] | ||||||
| 2021 Tesla Model 3 Standard Range Plus RWD - All years, all fuels | 2021 | 142 mpg-e | 150 mpg-e | 133 mpg-e | ||
| 2022 Tesla Model 3 RWD - Current Year, all fuels | 2022 | 132 mpg-e | 138 mpg-e | 126 mpg-e | ||
| 2022 Hyundai Ioniq Blue - Current year, gasoline fuel | 2022 | Hybrid electric | 59 mpg | 58 mpg | 60 mpg | |
| 2022 Hyundai Ioniq Blue - All years, gasoline fuel | 2022 | 59 mpg | 58 mpg | 60 mpg | ||
| Green Car Journal - Green Car of the Year | ||||||
| Chevrolet Bolt EV - 2017 Award[52] | 2017 | Electric car | 119 mpg-e | 128 mpg-e | 110 mpg-e | |
| Chevrolet Volt (second generation) - 2016 Award[53] [54] | 2016 | Gas equivalent All-electric mode | Gasoline only mode | All-electric range | ||
| 42 mpg | 53 mi | |||||
| BMW i3 - 2015 Award[55] | 2014 | Electric car | 124 mpg-e | 137 mpg-e | 111 mpg-e | |
| Honda Accord ninth generation line-up - 2014 Award[56] | 2014 | Gasoline hybrid and plug-in variants | mim 29 mpg, hybrid 47 mpg, plug-in 115 mpg-e[57] | |||
| Ford Fusion 2nd gen line-up - 2013 Award[58] | 2013 | mim 34 mpg, hybrid 47 mpg, plug-in 100 mpg-e | ||||
| Honda Civic GX - 2012 Award[59] | 2012 | Natural gas | 28 | 24 | 36 | |
| Chevrolet Volt - 2011 Award[60] [61] [62] | 2011 | Gas equivalent All-electric mode | Gasoline only mode | All-electric range | ||
| 37 mpg | 35 mi | |||||
| Green Car Journal - Green Car Vision Award | ||||||
| Ford C-Max Energi - 2012 Award[63] | 2013 | Gas equivalent All-electric mode | Gasoline only mode | All-electric range | ||
| Ford Focus Electric - 2011 Award[64] | 2012 | Gasoline equivalent fuel economy | All-electric range | |||
| 100 mi | ||||||
| Nissan Leaf - 2010 Award[65] [66] | 2011 | Gasoline equivalent fuel economy | All-electric range | |||
| 73 mi | ||||||
| Chevrolet Volt - 2009 Award[67] | 2011 | Gas equivalent All-electric mode | Gasoline only mode | All-electric range | ||
| 37 mpg | 35 mi | |||||
| World Car of the Year - World Green Car | ||||||
| Toyota Mirai - 2016 Award[68] | 2016 | 66 mpg-e | 66 mpg-e | 66 mpg-e | ||
| BMW i8 - 2015 Award[69] [70] | 2015 | Gas equivalent All-electric mode | Gasoline only mode | All-electric range | ||
| 28 mpg | 15 mi | |||||
| BMW i3 - 2014 Award[71] | 2014 | Gasoline equivalent fuel economy | All-electric range | |||
| 81 mi | ||||||
| Tesla Model S - 2013 Award[72] | 2013 | Electric car (60/85 kWh battery) | Gasoline equivalent fuel economy | All-electric range | ||
| 208/265 mi | ||||||
| Mercedes-Benz S 250 CDI BlueEFFICIENCY - 2012 Award | 2012 | 5.7L/100 km | ||||
| Chevrolet Volt - 2011 Award[73] | 2011 | Gas equivalent All-electric mode | Gasoline only mode | All-electric range | ||
| 37 mpg | 35 mi | |||||
| Volkswagen BlueMotion - 2010 Award[74] (Golf, Passat, Polo) | 2010 | n.a. | n.a. | n.a. | ||
| Honda FCX Clarity - 2009 Award[75] (miles per kilogram of hydrogen) | 2009 | Hydrogen fuel cell | 59 mpg-e | 58 mpg-e | 60 mpg-e | |
| Consumer Reports Top Picks: Green Car Category | ||||||
| Tesla Model S - Best overall model 2014 | 2014 | Electric car (60/85 kWh battery) | Gasoline equivalent fuel economy | All-electric range | ||
| 208/265 mi | ||||||
| Toyota Prius - Best green car 2014[76] | 2014 | 50 | 51 | 48 | ||
| Toyota Prius - Best green car 2013[77] | 2013 | 50 | 51 | 48 | ||
| Toyota Prius - Best green car 2012[78] | 2012 | 50 | 51 | 48 | ||
| Toyota Prius - Best green car 2011[79] | 2011 | 50 | 51 | 48 | ||
| Toyota Prius - Best green car 2010[80] | 2010 | 50 | 51 | 48 | ||
| Toyota Prius - Best green car 2009[81] | 2009 | 46 | 48 | 45 | ||
| Consumer Reports American Top Picks: Green Car Category | ||||||
| Ford Fusion Hybrid - Top Pick 2011[82] | 2011 | 39 | 41 | 36 | ||
| Ford Fusion Hybrid - Top Pick 2010[83] | 2010 | 39 | 41 | 36 | ||
| Ford Escape Hybrid - Top Pick 2009[84] | 2009 | 32 | 34 | 31 | ||
| What Car? Green Awards | ||||||
| BMW 320d Efficient Dynamics - Overall Winner 2012[85] | 2012 | UK combined 56mpgimp | ||||
| Vauxhall Ampera - Overall Winner 2011[86] | 2012 | Plug-in hybrid | EC combined 235.4mpgimp[87] | |||
| Toyota Auris Hybrid - Overall Winner 2010[88] | 2010 | UK combined 74mpgimp | ||||
| Volvo S40 1.6D DRIVe S - Overall Winner 2009[89] | 2009 | UK combined 60mpgimp[90] | ||||
| Ford Focus 1.6 TDCi Style - Overall Winner 2008[91] | 2008 | UK combined 52mpgimp[92] | ||||
| Mother Earth News Best Green Cars | ||||||
| Best Green Cars of 2011[93] | ||||||
| Chevrolet Volt | 2011 | Gas equivalent All-electric mode | Gasoline only mode | All-electric range | ||
| 37 mpg | 35 mi | |||||
| Nissan Leaf | 2011 | Gasoline equivalent fuel economy | All-electric range | |||
| 73 mi | ||||||
| Toyota Prius | 2011 | 50 | 51 | 48 | ||
| 2011 | Gasoline | 33 | 29 | 38 | ||
| Honda CR-Z CVT | 2011 | Hybrid electric | 37 | 35 | 39 | |
| VW Jetta TDI | 2011 | 34 | 30 | 42 | ||
| Best Green Cars of 2010[94] | ||||||
| Ford Fusion Hybrid | 2010 | 39 | 41 | 36 | ||
| align=left | Honda Civic Hybrid | 2010 | Hybrid electric | 42 | 40 | 45 |
| Honda Insight | 2010 | 41 | 40 | 43 | ||
| Toyota Prius | 2010 | 50 | 51 | 48 | ||
| VW Golf TDI | 2010 | 34 | 30 | 42 | ||
| VW Jetta TDI | 2010 | 41 | 40 | 43 | ||
| American Council for an Energy-Efficient Economy Greenest Vehicles of the Year | ||||||
| Greenest Vehicles of 2012 (Top 5)[95] | ||||||
| Mitsubishi i-MiEV | 2012 | 3.8 mile/Kwh | 2.9 mile/Kwh | |||
| Honda Civic GX | 2012 | Natural gas | - | 27mpg-e | 38 mpg-e | |
| Nissan Leaf | 2012 | 2.7 mile/Kwh | ||||
| Toyota Prius | 2012 | 50 | 51 | 48 | ||
| Honda Insight | 2012 | 42 | 41 | 44 | ||
| Greenest Vehicles of 2011 (Top 5)[96] [97] | ||||||
| Honda Civic GX | 2011 | Natural gas | 28 | 24 | 36 | |
| Nissan Leaf | 2011 | 2.72 mile/Kwh | ||||
| Smart fortwo (Cabriolet/Coupe) | 2011 | 36 | 33 | 41 | ||
| Toyota Prius | 2011 | 50 | 51 | 48 | ||
| align=left | Honda Civic Hybrid | 2011 | Hybrid electric | 41 | 40 | 43 |
| Greenest Vehicles of 2010 (Top 5)[98] | ||||||
| Honda Civic GX | 2010 | Natural gas | 28 | 24 | 36 | |
| Toyota Prius | 2010 | 50 | 51 | 48 | ||
| align=left | Honda Civic Hybrid | 2010 | Hybrid electric | 42 | 40 | 45 |
| Smart fortwo (Convertible/coupe) | 2010 | 36 | 33 | 41 | ||
| Honda Insight | 2010 | 41 | 40 | 43 | ||
| Kelley Blue Book Top 10 Green Cars | ||||||
| Top 10 Green Cars of 2014 (Top 5)[99] | ||||||
| BMW i3 | 2014 | Gasoline equivalent fuel economy | All-electric range | |||
| 81 mi | ||||||
| Nissan Leaf | 2014 | Gasoline equivalent fuel economy | All-electric range | |||
| 73 mi | ||||||
| Toyota Prius | 2014 | 50 | 51 | 48 | ||
| Tesla Model S | 2014 | Electric car (60/85 kWh battery) | Gasoline equivalent fuel economy | All-electric range | ||
| 208/265 mi | ||||||
| Honda Accord Hybrid | 2014 | 47 | 50 | 45 | ||
| Top 10 Green Cars of 2011 (Top 3)[100] [101] | ||||||
| Nissan Leaf | 2011 | Gasoline equivalent fuel economy | All-electric range | |||
| 73 mi | ||||||
| Chevrolet Volt | 2011 | Gasoline equivalent fuel economy | All-electric range | |||
| 35 mi | ||||||
| Toyota Prius | 2011 | 50 | 51 | 48 | ||
| Top 10 Green Cars of 2010 (Top 3)[102] [103] | ||||||
| Toyota Prius | 2010 | 50 | 51 | 48 | ||
| Honda Insight | 2010 | 41 | 40 | 43 | ||
| Ford Fusion Hybrid | 2010 | 39 | 41 | 36 | ||
See also: Motor show.
Dedicated electric and green vehicle motor shows: