Market Trends

Model year 2007 sees a number of exciting new developments unfolding on showroom floors. The hybrid-electric vehicle (HEV) market, which has already branched into most major vehicle classes, receives another couple high-profile nameplates this model year in the Toyota Camry Hybrid and Nissan Altima Hybrid. Each averaging 39 miles per gallon in combined city/highway driving, these cars offer new options to consumers seeking clean and ultra-efficient mobility in a midsize sedan. Unfortunately for consumers, the Altima Hybrid will only be available in California and a handful of states that have adopted California's emissions requirements. It is our hope that Nissan will expand availability of the Altima Hybrid so that hybrid enthusiasts nationwide have the opportunity to enjoy the vehicle. More broadly, the hybrid market saw continued growth over the past year with the sale of an additional quarter-million units, bringing the total number of hybrid on U.S. roads to roughly 620,000 through the end of 2006. Federal and state tax credits played an important role helping purchasers subsidize the higher up-front costs associated with hybrids. Similarly, high gasoline prices played a key role in raising consumer awareness about the importance of fuel economy in vehicles of all types.

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. Although the concept has been around for a few decades, it was not until recently that advanced computer control allowed for an effective cylinder deactivation design. Known under branded names such as "Multi-Displacement System" (DaimlerChrysler), "Active Fuel Management" (GM), or "Variable Cylinder Management" (Honda), this technology offers modest fuel economy improvements with no loss of performance. In other conventional vehicle developments, greater numbers of passenger cars and trucks are being certified to cleaner and cleaner tailpipe standards. Thanks in large part to the continued phase-in of tailpipe emissions standards launched in 2004, today's vehicles' overall contributions to smog-forming pollutants continue to decline.

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. Consequences of an inefficient vehicle fleet became acutely visible when Hurricanes Katrina and Rita bore down on the Gulf Coast in 2005. 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. Even in the comparatively calm months following Hurricane Katrina, Americans still found themselves at the mercy of not only thin refining capacity margins, but real and perceived threats to a steady Middle East oil supply that pushed average pump prices above $3.00 per gallon. Prices barely budged from May through August, despite a surprisingly calm 2006 hurricane season. And while a number of SUVs and other large trucks saw declining sales in the face of looming gasoline prices, the auto industry offered steady incentives to buoy these vehicles' market shares.

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. While early on these emissions requirements translated to only modest emissions reductions, significant changes are beginning to occur. For example, model year 2006 marked the end of the Phase I low emission vehicle program, so this year all California-certified models must meet one of the cleaner Phase II low emission vehicle standards (e.g., LEV II, ULEV II, etc.). Because most models are dual-certified to both a California and a federal standard, this requirement has had the effect of dramatically increasing the number of models being certified to the respectable federal Tier 2 bin 5 standard (which corresponds to the now least-stringent California certification, LEV II). Between model years 2006 and 2007, the number of nameplates available with a Tier 2 bin 5 certification increased 55 percent from 248 to 386.

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 to more than 50 in 2007. 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 Impala, Ford Fusion, Honda Accord, Mazda 6, Mitsubishi Outlander, Nissan Altima, Pontiac Grand Prix, Subaru Outback, Toyota Camry, Volkswagen Jetta, and Volvo V50. Unfortunately, because these vehicles require additional hardware and software controls (thereby making them a couple-hundred dollars more expensive than their less-clean counterparts), many automakers have chosen to sell SULEV and PZEV models only in California and the other clean car states where they are mandated. Nonetheless, there is a small but growing contingent of nationally-available PZEV models. The 2007 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 have to date kept 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. Automakers are aware of the interest in this technology and have incorporated plug-in features into concept cars like Chevrolet's Volt and Ford's Flexible Series Hybrid Edge. 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. If developments in battery technology over the next few years are successful, however, a plug-in option with modest electric-only range could become standard on the next wave of hybrid-electric vehicles.

Compressed natural gas (CNG)-powered vehicles also continue to score extremely well. This year, Honda's Civic GX claimed the prize as the greenest vehicle of the year. For buyers with access to compressed natural gas, model year 2007 offers factory-built vehicles in a few different sizes. The Civic GX offers extremely low emissions levels with good driving range. At the other end of the size spectrum, a 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 still not big sellers. They are mostly purchased by fleets, 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 states that have or are soon to adopt California's emissions requirements, including California, Connecticut, Maine, Massachusetts, New Jersey, New York, Oregon, Pennsylvania, Rhode Island, Vermont, or Washington state (or in some instances, neighboring states to these), 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 also a give-and-take between consumers and manufacturers. As more and more consumers adopt the notion of buying green, 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 2007

This year, the natural gas-powered Honda Civic GX claims the title as the greenest vehicle of the year. Toyota's hybrid-electric Prius, which places second, is the year's top-scoring gasoline vehicle, while Honda's Civic Hybrid ranks a close third. Rounding out the top five are the recently released Nissan Altima Hybrid and Toyota Yaris. In total, the Greenest Vehicles list contains one natural gas, four hybrid-electric, and seven conventional gasoline vehicles, a mix of technologies that demonstrates some of the avenues automakers have taken in developing greener vehicles. 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. Honda's hybrid-electric Insight, a perennial top-scoring model since its debut in model year 2000, was discontinued last year, while a host of new clean-and-efficient models for 2007 such as the Honda Fit, Nissan Altima Hybrid, Toyota Camry Hybrid and Toyota Yaris, joined the pack. While not a new model, Hyundai's PZEV-certified Elantra also makes its debut in the top-twelve list this year thanks to improved fuel economy. Perhaps one of the more interesting things about this year's list is what you don't see on it: the numerous other green vehicles that just missed the cut. Models such as the Mazda 3, Ford Focus, Chevrolet Cobalt, Pontiac Vibe, and Ford Escape Hybrid, all of which held court in previous years' Greenest Vehicles lists and still score very well, haven't left the market; the competition's just gotten a little stiffer. This is, of course, good news to consumers, who have greater options when it comes to buying the greenest vehicle that meets their needs and fits their budget.

Other good news is the fact that the vast majority of the year's greenest vehicles are widely available coast-to-coast. Not too long ago, the list was dominated by vehicles for sale only in California, while today more than 80 percent of the Greenest Vehicles can be purchased in any state.

Diesels and Light Trucks: Still A Concern

Our list of the year's 12 Meanest Vehicles for the Environment has traditionally been dominated by large SUVs and pickups with 8 or more cylinders per engine and four-wheel drive. After all, moving more metal (or moving it faster) means burning more fuel, which therefore causes more pollution unless extra steps are taken to control it. Model year 2007, however, sees an interesting development in the introduction of a number of diesel-powered SUVs and crossovers that meet some of the dirtiest standards still allowable in the country. Although these engines offer an efficiency improvement over comparable gasoline models, the poor tailpipe emissions performance of the diesel models is sufficiently damaging to the environment that it earns them a place on the year's Meanest Vehicles list. This year, nearly half of the list is populated by these diesel models, including the 3.0-liter diesel Jeep Grand Cherokee; Mercedes-Benz GL320 CDI, ML320 CDI, and R320 CDI; and the year's meanest vehicle for the environment, Volkswagen's 5.0-liter diesel Touareg.

Curiously, the manufacturers of these diesel models have already unveiled plans to bring cleaner diesel models to the country in 2008 containing more sophisticated emissions control systems that purportedly will meet the Tier 2 bin 5 emission standard. Mercedes-Benz, in fact, already has a diesel model on the market meeting the Tier 2 bin 8 standard, which is about two-thirds cleaner than the Tier 2 bin 10 standard to which the models on this list are certified. While reasoning behind DaimlerChrysler's decision to unveil a dirty diesel model for 2007 remains unclear, it is likely these models will only temporarily be on the market in this configuration.

Diesels aside, the remainder of the Meanest Vehicles list is populated with large pickups, large SUVs, and exotic sports and luxury cars. The modest sales volumes of the latter mitigate concern about those vehicles, though the same cannot be said for pickups and SUVs, which even despite high gasoline prices are still seeing continued market interest. 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 recently discontinued Honda Insight were 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 Toyota Yaris decreases CO2 emissions by 1.8 tons over 15,000 miles of annual driving, driving a massive SUV like a Lincoln Navigator instead of an average car increases annual CO2 emissions by 4.9 tons-negating the amount of global warming pollution that's avoided by close to three Insights. In other words, to really cut CO2 emissions, higher fuel efficiency in big as well as small vehicles will be essential.

With the advent of the Tier 2 tailpipe standards, which will eventually eliminate the car/light truck distinction for emissions purposes, 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 not uncommon.

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 began marketing these vehicles for passenger use in the early '90s, pushing their sales beyond car sales 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.

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 has made them exempt from fuel economy laws and, prior to Tier 2, 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 larger Dodge Ram pickups, 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.

In the spring of 2006, administrative adjustments to the fuel economy requirements of passenger trucks were made that will bring these heavier SUVs under fuel economy standards beginning in 2011. Despite strong lobbying from the environmental community to fold all Class 2B trucks into fuel economy regulations, large pickups, including all 250/2500-series and up (and even some 150/1500-series pickups), are still omitted from any fuel economy regulations. Furthermore, the standards have been restructured to vary with vehicle size, so that larger vehicles will be subject to more lenient fuel economy requirements.

The average fuel economy of all new cars, passenger vans, SUVs, and pickups has declined over the past two decades. According to EPA, the average fuel economy of model year 2006 passenger vehicles was 21.0 MPG, lower than it was even in model year 1982. And while fuel economy has crept up slightly over the past few years, it will not reach the 1987-88 peak of 22.1 MPG until 2010 at the earliest, unless buying habits change. The main reason for this drop is historical growth in the market of large SUVs and pickups. These leather-lined "trucks," which saw steady sales growth throughout the '90s and into this decade, are no more fuel-efficient than their less luxurious predecessors.

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 vans like the GMC Savanna Passenger van 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 people.

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 Chevrolet's Avalanche, 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), today designed to run on either gasoline or the alcohol-gasoline blend known as E85 (85 percent ethanol, with 15 percent gasoline), can automatically detect the fuel put into the tank.

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 and GHG 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. A number of automakers are aggressively marketing FFVs in national ad campaigns (such as GM's "Live Green Go Yellow" campaign), and making them widely available to the general market in a number of models. The 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 in less than one 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.