Model year 2006 sees the continued growth of the hybrid market, as well as an increase in the selection of vehicles with extremely low tailpipe emissions. Hybrid-electric vehicles (HEVs) branch out into the mid-size sport utility category this year with the introduction of the Toyota Highlander Hybrid and Lexus RX 400h. Averaging around 30 miles per gallon while achieving the cleanest tailpipe emissions ever of a mid-size SUV, these vehicles are proof that clean, efficient vehicles can be produced in virtually any format. Echoing that sentiment is the new Mercury Mariner Hybrid, twin to last year's notable newcomer, the Ford Escape Hybrid. Offering a 40 percent improvement in fuel economy over the 4wd gasoline Mariner, the Mariner Hybrid offers a new, upscale spin on Ford's eco-friendlier SUV.
On the conventional vehicle front, models continue to receive advanced, environment-friendly technologies. Cylinder deactivation, the recent fuel-saving engine design in which some cylinders shut off when maximum power is not needed, is being incorporated into greater numbers of vehicles this year. Known under branded names such as "displacement on demand" (Chrysler), "active fuel management" (GM), or "variable cylinder management" (Honda), this technology offers modest fuel economy improvements with no loss of performance. Furthermore, thanks in large part to tailpipe emissions standards launched in 2004, a greater number of new conventional models are being certified to cleaner and cleaner tailpipe standards, reducing today's vehicles' overall contributions to smog-forming emissions.
In spite of such promising developments, however, the car and truck market is still headed down a road of environmental harm. Overall vehicle fuel economy continues to stagnate, while oil dependence and global warming pollution continue to rise. The constraining consequences of an inefficient vehicle fleet became acutely visible this past year, as Hurricanes Katrina and Rita bore down on the Gulf Cost. A fuel market already strained by inadequate refining capacity saw prices escalate even further as supplies rapidly waned. Numerous residents, eager to evacuate, found themselves on gridlocked highways with limited or no fuel. Even the hurricanes themselves, argue some climatologists, were aggravated by global warming pollution caused by the burning of fossil fuels.
These impacts are not without cause. On average, every new large SUV cruising the streets produces 60 percent more climate-threatening carbon dioxide (CO2) emissions than a new car. While ultra-efficient models such as the Honda Insight are capable of cutting CO2 emissions by over 50 percent compared to similarly sized cars, small vehicles already have above-average efficiency and therefore produce less CO2 than most models on the road. So, while driving an Insight instead of a Mini Cooper decreases CO2 emissions by 2.9 tons over 15,000 miles of annual driving, driving a massive SUV like a Hummer H2 instead of an average car increases annual CO2 emissions by 5.2 tons-negating nearly the amount of global warming pollution that's avoided by two Insights. In other words, to really cut CO2 emissions, higher fuel efficiency in big as well as small vehicles will be essential.
Thanks to the regulatory pressure on automakers by the U.S. Environmental Protection Agency (EPA), the California Air Resources Board (CARB), and several other state environmental agencies, cars and trucks are headed in the right direction in terms of lower smog-forming tailpipe pollution. Model year 2004 marked the official start of California's LEV II and the Federal government's Tier 2 emissions programs, and their phase-ins continue this year. Although these programs are responsible for an increasing number of super-clean models being released with tailpipe emissions never before seen in conventional vehicles, the regulations have been written with a significant amount of flexibility during the early years of their phase-in. This translates to modest emissions reductions on the whole today, although, over the next few years, the overall impact of these programs will become substantial.
The super-clean, or so-called Super-Ultra-Low-Emission Vehicles (SULEVs) are, in many cases, also receiving a special California regulatory designation as Partial Zero-Emission Vehicles (PZEVs) for, among other things, having greater emissions control system durability and emitting near-zero levels of evaporative hydrocarbons. This year, SULEVs and PZEVs-emission levels not associated with gasoline vehicles even just a few years ago-are increasingly common in conventional vehicles. The number of gasoline nameplates meeting these standards has climbed steadily in recent years, reaching a total of 37 in 2006. And this progress in cutting-edge emissions control is not limited to fringe models. SULEVs and PZEVs are available this year in-to name a few-the Buick LaCrosse, Chevrolet Cobalt, Ford Fusion, Honda Accord, Mazda 3, Mitsubishi Galant, Nissan Altima, Subaru Outback, Toyota Camry, Volkswagen Jetta, and Volvo S60. Unfortunately, because these vehicles require additional hardware and software controls (thereby making them more expensive than their less-clean counterparts), many automakers have chosen to sell SULEV and PZEV models only in California and the New England region where they are mandated. Nonetheless, there is a small but growing contingent of nationally-available PZEV models. The 2006 Honda Civic Hybrid, for example, is sold nationwide carrying a dual-certification of PZEV and Tier 2 bin 2.
Battery-powered or "plug-in" electric vehicles (EVs) in prior years earned high Green Scores in our listings, but these models have since been discontinued. EVs appeal to some consumers for their high-tech design, quiet operation, ability to recharge at home, independence from petroleum, and simply because they are among the cleanest cars available. However, batteries have a high cost and limited range, and these constraints keep EVs from being a practical choice for most consumers. Recently, advocates outside the auto industry have promoted the idea of a crossbreed of an EV and a hybrid, known as a plug-in hybrid-electric vehicle (PHEV). This design concept overcomes the range limitations of EVs and may one day become a green vehicle option for consumers. At this time, however, no automakers are producing plug-in hybrids since they face many of the same battery- and cost-related barriers constraining EVs.
Compressed natural gas (CNG)-powered vehicles also continue to score extremely well. This year, Honda's Civic GX placed a narrow second (to the Honda Insight) in the bid for the year's greenest vehicle. For buyers with access to compressed natural gas, model year 2006 offers factory-built vehicles in a few different sizes. The Honda Civic GX, for example, offers extremely low emissions levels with good driving ranges. At the other end of the spectrum, a bi-fuel compressed natural gas option is being offered by General Motors in their heavy duty pickup line. While not having the range and cost limitations of EVs, CNG cars and trucks are a more common choice for fleet buyers than for the average consumer due to the need for access to natural gas fueling stations.
Greener Choices for Everyone
In fact, everyone can buy green. The most environmentally friendly step you can take is simple: first evaluate your needs and your budget; then look for the models with the greenest scores among the cars and trucks that meet your needs and fit your budget. Even though some of our top ratings go to natural gas-powered vehicles or gasoline vehicles sold in limited areas, every class has nationally available gasoline vehicles that score significantly better than average.
Our Greener Choices table highlights some of the top-scoring gasoline vehicles in several segments of the market. The list includes only automatics, although many manual transmission versions have higher fuel economy. The excluded models that score even better might be good choices for some buyers. The point of the Greener Choices table is to show that there are ways to buy a cleaner and more efficient vehicle throughout the market.
The models listed in the Greener Choices table are available in most states. If you live in California, Massachusetts, New York, Vermont, Maine, Rhode Island, or Connecticut (or, in many instances, neighbors of these states), cleaner versions of the Greener Choices models may be available to you.
It is also useful to look not only at the models in this table, but at competing models as well, since within a given size class, the better vehicles often score similarly. Thus, the Greener Choices table can get you focused on the set of models that will be among the best in their class in terms of environmental friendliness.
Buying green does more than fulfill your own personal commitment to protect the environment. Each greener choice by an individual consumer, of course, reduces pollution directly. But the market is a give-and-take between consumers and manufacturers. As more and more consumers adopt green buying, automakers will begin to look at environmentally friendly design as an opportunity, not just an obligation. Such feedback will motivate car companies to make further investments in improved technology, so that an expanded number of green cars and trucks will be available in the years ahead.
Finally, bear in mind that the average car or light truck is likely to be operational for a dozen or more years. Even if you don't keep your new vehicle for more than a few years, your choice affects the options available for used car buyers. So instead of having yet another gas-guzzler cruising the streets, the greener choice you make today can help cut pollution for years to come.
The Greenest of 2006
This year, the automatic transmission, Super-Ultra-Low-Emissions (SULEV) version of Honda's hybrid-electric two-seater Insight is the greenest vehicle of the year. Honda's natural gas-powered Civic GX places a very close second. Toyota's hybrid-electric Prius again holds claim to the greenest gasoline-powered sedan, while the top five are rounded out by Honda's newly updated Civic Hybrid and Toyota's conventionally-powered Corolla. This diverse mix of vehicle technologies highlights a number of the avenues automakers have taken in developing greener cars and trucks. Whether using hybrid gasoline-electric designs, compressed natural gas, or simply clean and efficient conventional gasoline designs, automakers have visibly demonstrated their ability to engineer with the environment in mind.
This year sees a number of changes to the nameplates on the Greenest Vehicles list. Models such as the Toyota Echo, Nissan Sentra CA and Honda Civic HX have been discontinued, making room for the latest wave of clean-and-efficient conventional vehicles: the Hyundai Accent, Kia Rio (and Rio 5), Honda Civic, Chevy Cobalt, and Saturn Ion. This new crop of eco-friendly models was large enough, in fact, that it bumped last year's notable newcomer-the (still superbly scoring) Ford Escape Hybrid SUV-off of this year's list.
But perhaps the best green consumer news is that the vast majority of the year's greenest vehicles are widely available coast-to-coast. While previous years saw the list dominated by vehicles for sale only in California, today about three-quarters of the Greenest Vehicles can be purchased in any state. Other good news is that nearly all of this year's Greenest Vehicles are gasoline-powered models. Not long ago, the list was largely populated by electric and other alternative vehicles. Today, eleven of the twelve listings are fueled by gasoline.
Light Trucks-Most Still Score Poorly
Our list of this year's 12 Meanest Vehicles for the Environment is once again dominated by large SUVs and pickups with 8 or more cylinders per engine and four-wheel drive. In short, moving more metal (or moving it faster) means burning more fuel, which therefore causes more pollution unless extra steps are taken to control it. If large light trucks were used mainly for true heavy-duty hauling, fewer would be sold and their pollution would be less of a problem. But automakers have been marketing these vehicles for passenger use, pushing their sales into the millions and creating a rapidly growing source of global warming pollution. By and large, automakers continue to lag in their overall efforts to improve SUV and pickup fuel economies.
With respect to tailpipe emissions, many automakers are now installing improved tailpipe controls on some of their minivans, pickups, and SUVs. While this partially addresses the tailpipe emissions problem, dirtier versions of these light trucks, meeting the bare minimum of pollution control requirements, are still commonplace.
Since our Green Scores reflect both fuel economy and tailpipe emissions, the high fuel consumption alone suffices to push down the environmental ratings of the largest light trucks. Some of the largest SUVs are so massive that they are classified as heavy duty (or "Class 2B") trucks, which makes them exempt from fuel economy laws and subject to weaker tailpipe standards. The U.S. "Big 3" automakers (DaimlerChrysler, Ford, and General Motors) continue to take advantage of this situation. Models like the Hummer H2 or Ford F-250 are designed to be just a bit heavier than the cut-off for fuel economy standards. Weight ratings of some Dodge Ram pickups and Chevrolet Suburbans have also been pushed up to avoid fuel economy standards. Administrative adjustments to the fuel economy requirements of passenger trucks were proposed in the summer of 2005; despite strong lobbying from the environmental community to fold Class 2B trucks into fuel economy regulations, the proposed rule omits such a requirement.
The average fuel economy of all new cars, passenger vans, SUVs, and pickups has declined over the past decade. According to EPA, the average fuel economy of model year 2005 passenger vehicles was 21.0 MPG, lower than it was even in model year 1982. And while fuel economy has crept up slightly during the past few years, it still sits well below the 1987-88 peak of 22.1 MPG. The main reason for this drop is that you can now buy a huge, leather-lined sport utility with any one of many luxury marquees. And while sales of such "trucks" are high, they are no more fuel-efficient than their less luxurious predecessors of a decade ago.
If you usually carry multiple passengers in your SUV or minivan, however, the environmental impact per passenger is lower than if you drive alone. Similarly, pickup trucks would be more environmentally friendly if regularly used to carry the loads for which they are designed. Thus, a light truck can be "green" when its capacity is put to good use. For example, while large passenger vans like the Ford E-250 or GMC Savanna end up at the low end of our rankings because they score poorly, they may not really be "mean," since they're used primarily for carrying multiple passengers.
It's a Car. It's a Truck. It's a...Crossover Vehicle.
The last few years have seen the boundaries between cars, pickup trucks, and SUVs becoming less and less clear with the introduction of numerous vehicles featuring both car-like handling and SUV-like spaciousness and functionality. These so-called "crossover" vehicles, including SUVs with pickup truck beds, station wagons with SUV-like off-road abilities, and altogether new vehicles that defy conventional categories, have been hitting the streets with great popularity. Some of these vehicles are variations on the heavy-and-rugged sort, such as Cadillac's Escalade EXT, a SUV/pickup crossbreed. Volvo's XC70 and XC90 walk the line between touring wagon and all-purpose utility vehicle. Head-turners like the Chevrolet HHR and Mazda 5 don't readily fit the classification of either a car or a truck.
What this newfound popularity in crossover vehicles means for consumers is greater choice in styling and functionality. For some people, a crossover may serve as well as (or better than) a SUV or pickup truck for hauling goods around. For others, crossovers may offer the extra functionality not found in conventional cars. Either way, automakers are capitalizing on the uniqueness of these new vehicles, which have become a market segment unto their own.
So how do crossover vehicles rank environmentally? Not surprisingly, with the exception of the massive SUV/pickup combos, they generally score better than trucks, yet worse than cars. This is largely because their fuel economies fall between those of cars and trucks. Ultimately, the environmental benefit of crossover designs depends upon how they're used: for zipping around town, they won't be saving the planet, but they can offer a greener alternative to SUVs for ski trips to the mountains.
Because crossover vehicles don't fit exactly into the vehicle classes designated on this site, they have been listed in the class to which they are most related or that best reflects their position in the market. Keep in mind that while each listing's class ranking (superior to inferior) compares it to others in the same vehicle class, the Green Score is not class-specific, and can be used to compare vehicles among any classes. So the Green Score will often be the best way to evaluate crossover models.
Bi- and Flex-Fuel Vehicles
A number of automakers are now offering vehicles with bi-fuel capability, meaning the ability to run on either an alternative fuel or gasoline. For example, some pickup trucks can be set to run on compressed natural gas (CNG) or gasoline, depending on what fuel is available to the driver. Flexible-fuel vehicles (FFVs) can automatically detect the fuel put into the tank, typically the alcohol-gasoline blend known as E85 (85 percent ethanol, with 15 percent gasoline).
ACEEE's Green Book® Online does not provide listings for bi- and flex-fuel vehicles since their environmental performance is not substantially different from that of their gasoline-only counterparts. In terms of tailpipe emissions, a bi-fuel CNG vehicle may be cleaner when running on CNG than when running on gasoline. FFVs may be cleaner when running on their alternative fuel, but in practice they rarely do. Some automakers are making FFVs widely available to the general market in a number of models, and renewed interest in ethanol as a tool to reduce U.S. oil dependence has led to a substantial increase in the number of fueling stations offering ethanol. But E85 is still available only in a fraction of a percent of filling stations, and many FFV drivers do not even know of their vehicles' alternative fuel capability. Nevertheless, automakers are getting higher credits toward their fuel economy requirements with every FFV they sell. Ironically, such sales are causing more pollution overall because of the corresponding decrease in fleetwide fuel economy. Thus, the credits for FFVs, while perhaps well-intentioned, are resulting in higher nationwide gasoline consumption, higher oil dependence, and worse global warming pollution than would otherwise occur.
