The best GPS for me, and you

With cars, we have become quite accustomed to the 4-5 year product cycle. This pattern sees a new model introduced,  a midlife update after 2-3 years, then the model is phased out or  replaced by a new, larger, more powerful, and pricier car.

But like other electronics, the fast-paced portable GPS navigation world is much different. There are now about 2-3 model cycles occurring each year, and the new models are typically sleeker, more feature packed, and sometimes less expensive than the models they replace.

Since we have accelerated our test program during the past 18 months, we’ve seen new abilities and features continually emerging. Many of these features truly improve the breed, or at least show great promise with further development. We have rated some excellent units, noting attractive Best Buys for their combination of features and price. But even recognizing how good today’s best units are, for my personal taste, there is not yet a single, do-it-all navigation device that hits all my hot buttons and sells for an attainable price. But I believe it is coming.

That hope brings excitement to testing each new product. Will this one be better than its predecessors? Just like with cars, I find myself often thinking, "The next generation will be perfect." I am still waiting.

As we have just added new units to Dash and Sony to our GPS ratings (available to online subscribers), and are now evaluating the next test group, I realize that GPS perfection may be  a never-ending quest. For now, if I could assemble a fantasy device from current units, my electronic platypus would include:

Ease of use—Garmin. From the moment you turn on any Garmin Nuvi, the interface is simple as can be. "Where to?" it asks. Being able to quickly find the destination you seek saves time and frustration. This is particularly valued if you have a passenger program the unit who may not be familiar with it or if you are a tech-averse, first-time GPS owner.

Wide screen—The larger screen width not only make the maps easier to read, but it can simplify address entry with larger on-screen buttons. Plus, I like using a split-screen with a large arrow indicating the next turn.

Spoken street names—Also known as "text to speech." Knowing exactly what street to turn on can reduce confusion, especially in urban settings. Driving through a major city, like New York, being told "Turn right" just isn’t specific enough.

Free traffic—Navigon 5100. Living in the greater NYC metropolitan area, traffic info is important to me. After all, the right information can mean the difference between domestic tranquility and a cold, lonely dinner. The MSN Direct service and Dash Driver Network both have proven to be useful services, with the Dash promising even more future potential. But, my life is overflowing with fees for other devices and I just can’t stomach one more. The free traffic information with the Navigon is similar to the data received from some other for-pay services. While not perfect, it is helpful and the price is right.

Historic traffic—TomTom, Dash. In my experience, so-called real-time traffic isn’t always up to the minute and still doesn’t adequately contend with rush-hour congestion. The increasing trend for units to tap historic traffic information means the route suggested at 8 a.m. may be different than the one proffered at noon, even if there isn’t a major accident. This is helpful for commuting to find better routes, and even more welcomed when traveling, where you simply don’t have local knowledge to predict likely traffic flow.

Reality view—Sony NV-U83T, NV-U73T, and TomTom 930, 730. Like latest Navigon units, these newer devices provide a so-called “reality view” that presents a simple graphic of an upcoming, major intersection, though their graphics are a touch more pleasing. I have found this feature to be very helpful in navigating complex highway interchanges, with clear guidance on the proper lanes to occupy.

Speed alerts—Integrated speed alerts can display the current speed limit and alert when it has been exceeded by a user-set amount. This can be a real help in unfamiliar areas where the speed limits rise and fall unexpectedly.

Processing speed—It can be frustrating to delay leaving on a road trip while a device seemingly flips endlessly through a card catalog to find and route to a POI, rather than whisking quickly through its electronic database.

Design—Give me a clean design that maximizes screen size, with a thin, non-reflective case. And place a hard-key button on the exterior for muting.

Best for you
As the innovation continues, more and more consumers will find the multi-function GPS devices to be an important tool in their mobile electronics inventory. However, it is the core navigation features that I want to see refined and gathered in a single, affordable model. To me, stuff like a video player or currency converters don’t contribute to the main purpose of a GPS device—just efficiently get me where I want to go.

So while the perfect GPS device (by my standards) may not yet exist, any online subscriber can quickly find the best GPS device available for their needs and budget using our dynamic ratings chart. Links from each product name will take you to a detailed product page, with our testers’ notes on the highs, lows, and bottom line.

If you buy a device, please return to the product pages once you’ve had some experience to share your insights with others via the user reviews. And rest assured, the GPS team will continue to rate models on our never-ending search for the perfect device.

In the meantime, what features matter most to you? Post your thoughts in the comments below.

—Jeff Bartlett

For more information on portable GPS navigation systems, see our Ratings and buying advice and watch our video guide. Discuss GPS devices in the forums. 

How Mercedes’ BlueTec works, and the 2009 clean-diesel SUVs to come

For automakers to bring the innate fuel efficiency of a diesel engine with peppy performance and low emissions to the U.S. market, it required a national change-over to ultra-low-sulfur diesel fuel, the development of precisely controlled engines, and extensive treatment of exhaust gases. With these goals accomplished, there is a wave of diesel-powered vehicles coming to America despite the price premium on diesel fuel.

Mercedes-Benz has been leading the movement with its 50-state-legal "clean diesels" featuring "BlueTec" technology that mark the culmination of years of scientific research, powertrain engineering, and market preparation. The resulting BlueTec diesels burn cleaner than most gasoline engines and exhibit superior fuel economy at the same time.

This month, Mercedes announced that it would offer a clean-diesel option for three of its 2009-model SUVs: the midsized ML- and R-Class, and the big GL-Class. All will use the same 210-hp, 3.2-liter diesel V6. These should be some of the most fuel-efficient SUVs on the road. Mercedes has estimated that the GL320 BlueTec will record an average of 24 mpg, some 20 to 40 percent better than a comparable gasoline engine. It should also be able to travel 600 miles on a single tank of fuel.

There may have been nothing inevitable about Mercedes’ particular choices for creating a clean diesel. Conceivably a roster of alternative technologies could have accomplished the same thing. Honda, Nissan, and Toyota are all developing clean-diesel technology and they’re apt to use their own strategies to bring them to fruition. But the Mercedes BlueTec system just happens to be the first practical mass-market application available in the United States.

What is BlueTec?
It’s the proprietary name for a series of engine technologies, filters, and catalysts that result in low emissions and high fuel economy. It starts with a high-pressure common-rail turbo direct injection diesel engine. "Common rail" refers to the method for injecting precisely the right amount of fuel directly into each cylinder at exactly the right moment. The turbocharger boosts horsepower, and the system recirculates the exhaust gas that powers it in order to consume any unburned fuel.

When exhaust gas leaves the engine, a multi-phase treatment process begins. By their nature, diesels tend to produce high levels of carbon monoxide, oxides of nitrogen known collectively as NOx, and particulate matter, also known as soot. Oxidation catalysts minimize the carbon monoxide and further reduce unburned hydrocarbons. A maintenance-free particulate filter, or soot trap, then reduces soot to nearly undetectable levels.

NOx emissions are the trickiest to deal with. NOx forms in the first place as a result of burning atmospheric air, and every lean-burning engine generates NOx as the ratio of fuel to air in the combustion cycle decreases. Current approaches to trapping or destroying NOx emissions all use catalysts that are vulnerable to degradation in the presence of sulfur. That’s why it was necessary to put the whole country on a diet of ultra-low-sulfur fuel.

Mercedes uses two strategies to deal with NOx, one for cars and one for SUVs. The E320 BlueTec sedan, which we tested last year, attacks NOx with a storage catalyst and a second catalyst called SRC (Selective Catalytic Reduction). Periodically the engine runs rich for a little while, which cleanly purges the NOx storage catalyst.

For heavier vehicles, such as SUVs, Mercedes has adopted a urea-injection system called AdBlue. That’s because the NOx trap technology used in cars would require too-frequent purging and thus reduce fuel economy.

The AdBlue system uses the SRC catalyst and a tank of liquid urea, which is misted into the exhaust stream. When the urea comes in contact with the hot exhaust gas, it releases ammonia, which in turn reacts with NOx and emerges as harmless nitrogen and water. The urea supply is said to be good for 10,000 miles, so it only needs to be refilled at the vehicle’s normal service intervals. Mercedes says that the AdBlue system reduces NOx emissions by 80 percent.

The Mercedes-Benz BlueTec SUVs are slated to go on sale this fall as 2009 models.

— Gordon Hard

Also read "A clean diesel' sedan tops a performance-tuned hybrid" (available to online subscribers).

Average gas prices—April 28, 2008

Gas prices continue their weekly rise.

National retail fuel price averages

Price

Change from last week

Regular gasoline/gallon	$3.60	↑ .10
Diesel fuel/gallon	$4.18	↑ .03

Regional regular gasoline prices

Price

Change from last week

East Coast	$3.60	↑ .12
-New England	$3.60	↑ .11
-Central Atlantic	$3.62	↑ .13
-Lower Atlantic	$3.59	↑ .11
Midwest	$3.57	↑ .10
Gulf Coast	$3.51	↑ .09
Rocky Mountain	$3.48	↑ .06
West Coast	$3.79	↑ .05
-California	$3.89	↑ .05

Source: Energy Information Administration, 4/28/08

As gas prices increase, consumption decreases

Have you noticed that there are fewer cars on the road lately? Recent trends seem to point in that direction. According to the Energy Information Administration (EIA), U.S. gasoline consumption has been declining for at least six months. In the first quarter of 2008 fuel demand was 1.4 percent below last year’s levels and it’s the third straight quarter of declines according to the American Petroleum Institute.

The EIA projects that for 2008, gasoline consumption is expected to decline by 0.3 percent. In particular, the summer (April through September) is expected to show a 0.4-percent decrease from last year. If you’re planning on hitting the road this summer, be prepared for sticker shock as regular retail gas prices are predicted to average $3.54 a gallon (up from $2.93 last summer) with some areas crossing $4.00.

With summer beyond the traditional time for road trips, it is no surprise that elevated fuel prices has lead to “staycations”—money-saving, stay-at-home vacations.

Another sign that people are changing their driving habits is the increase of public transportation use, which rose to its highest level in 50 years—10.3 billion trips in 2007, up 2.1 percent over the previous year. Americans are looking into alternative modes of transportation such as trolleys, trains, subways, and buses, which all showed a ridership increase, with the largest growth in major cities.

These fuel-consumption indicators are not surprising considering the rise in gas prices and slowing economy.

What steps have you taken, if any, to decrease your fuel consumption? Post your answers in the comments below.

To see what gas prices are in your area, see our average gas prices, which is updated weekly. Also, read our fuel saving tips and learn about alternative fuels in the Consumer Reports Guide to Driving Green.

—Liza Barth

Pressing matters - Toyota wasn’t alone in receiving government assistance

The automotive press was abuzz earlier this month as corporations flung around statements related to the development of hybrid vehicles, suggesting Toyota may have received an unfair advantage by receiving government funding for research and development. However, Toyota isn’t the only automaker to receive government assistance. More than a decade ago, American tax dollars supported an auto industry initiative to develop a marked advance focused on developing a marketable, 80-mpg family car.

This conflict flared up recently after Business Week magazine published a quote from Jim Press, former president of Toyota’s U.S. division: “The Japanese government paid for 100 percent of the development of the battery and hybrid system that went into the Toyota Prius.” In September 2007, Press left Toyota to become Chrysler’s vice chairman and president.

While Press’s statement may not sound earth shaking, the news rocked Detroit. The impression left is that Toyota received an unfair advantage (i.e., government support), when some captains of the American car industry have long justified their delay, both on and off the record, in developing hybrids by claiming that such complex vehicles can’t make money due to huge development costs. They may be right. Even if the Japanese government did help pay for the development of the Prius, that doesn’t necessarily make it profitable. (Jim Press is shown here at  the 2001 New York International Auto Show with first-generation Prius prepped for the transit authority.)

There is some dispute about the veracity or the details of Press’s claim. Toyota has refuted it. Chrysler has clarified the statements in a media-focused blog with “He said the Japanese government strongly supported R & D (research and development) investment in battery development, and the Prius and other Japanese models benefited from that investment in industry.” Yet, in testimony in 2007, Press told Congress that the Japanese government did not pay for any Prius research and development.

Whatever the truth may be, all the attention this story has generated may have left a false impression in readers’ minds. It implies that if only the U.S. government supported Detroit the way the Japanese government does Toyota, Detroit might not have lost the race to develop efficient, advanced hybrid cars.

A quick history lesson debunks this myth:

From 1993 to 2000, the United States did spend about $1.2 billion helping the American auto industry develop hybrids just like the Prius. The program was called the Partnership for a New Generation of Vehicles (PNGV). It was a joint effort between the Department of Energy, national laboratories, universities, and the Big 3 U.S. automakers (through a research consortium called USCAR). The goal was for each of the automakers to build a prototype family sedan that could achieve 80 mpg and cost no more than a similar conventional car.

Chrysler, Ford, and GM each produced prototypes that got at least 70 mpg: the Chrysler ESX3, Ford Prodigy, and General Motors Precept. All three were diesel-electric hybrids. But none of the companies have built such cars, as the original program mandate had envisioned, after PNGV was replaced by the fuel-cell focused FreedomCAR initiative in 2003.

According to a 2002 article in Issues magazine by Daniel Sperling, founding director of the Institute of Transportation Studies at the University of California at Davis and a member of the California’s Air Resources Board (commonly known as CARB), the PNGV had one other lasting effect: The prospect of the world’s richest country teaming with some of the world’s (then) largest automakers spurred Japan and Europe to develop similar task forces: the European Car of Tomorrow Task Force and the Japan Clean Air Program.

And unlike the U.S. companies, the fruits of Toyota’s participation in those efforts are visible on our roads every day.

—Eric Evarts

Discuss Hybrids and alternative fuel vehicles in the CR forums.

Crash avoidance technologies: Benefit or distraction?

Advances in car safety features, such as electronic stability control (ESC) have been proven to save lives and will be standard on all vehicles by the 2012 model year. Now a host a new safety features are making their way to the market place. Will these technologies be as widespread as ESC and become significant life saving features or will they become a distraction to drivers? A recent study by the Insurance Institute for Highway Safety (IIHS) takes a look at five new features and crash data from 2002-2006 to see how they can help prevent crashes.

Two features, forward-collision warning and lane-departure warning, are the most promising of these new technologies at helping to avoid crashes. Forward-collision warning helps to prevent front impacts by alerting drivers of the potential hazard with alarms, flashing lights, and/or on some vehicles, automatically applying the brakes.

There are more than two million front crashes—that’s 40 percent of the total number of crashes in a given year. If some of these crashes and the over 7,000 deaths that occurred from them could be prevented, then the potential benefit from this safety feature could significantly reduce injuries, related medical costs, emergency services, and repair bills. However, the IIHS warns that if drivers rely too much on technology to help them out or decide not to heed the warnings, then the benefit wouldn’t be as great.

Lane-departure warning alerts drivers, using a vibrating steering wheel, audible tone, or visual notice if they are moving out of their lane when a turn signal isn’t activated. In the period reviewed, there were almost 500,000 crashes per year and over 10,000 deaths from these accidents. A 2004 report from IIHS shows that textured pavement, known as rumble strips, have reduced head-on crashes and side swipes by 25 to 30 percent. If lane departure warning works just as well, the IIHS points out that feature could potentially eliminate more than 100,000 accidents and 2,500 deaths.

Three other safety features—blind-spot detection, adaptive headlights, and emergency brake assistance were also evaluated. Blind-spot detection helps keep track of vehicles in a blind spot by alerting drivers through a light by the side mirror or in some models, a beep. As my colleague Jim Travers notes in his recent blog, this warning can be distracting to drivers and can be turned off. There are 450,000 blind-spot-related crashes per year, but only a small number involve fatalities, limiting the benefit.

Adaptive headlights help drivers see better in nighttime driving by moving in the direction of the steering, but according to the IIHS, several studies show that drivers speed up when there are reflector posts or markers that indicate curves in the road. If this is the case, then drivers may also speed up if they have adaptive headlights.

Finally, emergency brake assist senses panic braking and prepares the brakes for extra pressure. This feature overlaps with the forward-collision warning and both systems are intended to prevent frontal crashes, so many of the crashes could be avoided by just the forward-collision warning, says the IIHS report.

Most of these technologies are relatively new and not available from all manufacturers. Volvo is the only manufacturer with all five technologies on some of its models, but other upscale brands such as BMW, Cadillac, and Mercedes-Benz are testing out some of these features. A recent Harris poll reveals that consumers showed an interest in purchasing blind-spot detection and lane-departure warning features, but the study also found that drivers still want control of their vehicles. Other studies show that automatic features tend to be the most effective as we have seen with existing features such as ESC and antilock brakes.

Only time will tell if these new safety features will reduce crashes and save lives, or if they may rely too much on driver response and become more of a distraction than a safety tool. Consumers shopping for a new vehicle should become familiar with the latest safety systems and seek models equipped with proven features, such as antilock brakes, side- and curtain air bags, and stability control. This latest report suggests that forward-collision warning and lane-departure warning systems are worth considering, as well.

—Liza Barth

Government proposes 31.6 mpg by 2015

In celebration of Earth Day yesterday, the Department of Transportation released an updated proposal on fuel economy standards that would require cars to get better gas mileage much sooner than previously scheduled.

The new standards would require vehicles to get 25 percent better fuel economy than the current standards by 2015. Cars alone would improve to 35.7 mpg in 2015, and light trucks to 28.6 mpg. Under a new Energy Bill that Congress passed last December, fuel economy requirements must improve by about 40 percent by 2020.

This proposal puts the bulk of that improvement at the beginning of the bill’s timeframe, from 2010 to 2015. This more aggressive timeline will likely drive the implementation of advanced technologies, such as direct fuel injection, sophisticated transmissions, and hybrid drive systems. By 2015, on average, new vehicles would be required to achieve about 31.6 mpg. The new rule would set different fuel-economy mandates for each automaker, based on the sizes and types of cars they build.

The proposalis expected to encourage manufacturers to install these fuel-saving technologies in all types of vehicles, from SUVs to small cars, rather than to simply build more small cars.

For the first time, the program will also allow automakers that exceed the new standards to sell credits earned under the program to other automakers that miss the targets. Otherwise automakers that don’t meet the targets would have to pay fines. In an interesting admission, the government has also assumed a monetary cost for CO2 emissions associated with global warming, as well as an energy security cost for petroleum consumption in setting the standards.

It goes without saying that demanding greater fuel economy improvements sooner will save significantly more fuel in the long run.

The government estimates that the proposal could save 55 billion gallons of fuel and save consumers more than $100 billion at the pump.

Now that’s something we can all celebrate.

—Eric Evarts

Also read:
"Charge! Fuel economy law promotes plug-in hybrids"
"New fuel economy standards won't bring real 35 mpg cars"

Discuss Hybrids and alternative fuel vehicles in the CR forums.

Drivers want safety features, but won’t give up control

Drivers are ready for new safety warning systems on their cars, but still want to keep control of their vehicle, according to the Harris Interactive 2008 AutoTechcast survey. This study found that half of respondents showed an interest in blind-spot detection technology and ranked it 10th out of 66 unique technologies for purchasing with their next vehicle. Twenty-nine percent of people said they were interested in purchasing a lane-departure warning system. The annual online survey was based on responses from 12,891 U.S. adults who own at least one vehicle.

While the survey found interest in these two new crash avoidance technologies, it also revealed that consumers would prefer their vehicles warn them so they can take the necessary action, instead of having the vehicle correct the situation on its own. In short, drivers are not ready to give up control of their vehicles.

Blind-spot detection systems warn the driver if a vehicle or object is within a vehicle’s blind spot. Nearly three-quarters of consumers in the survey indicated that they would prefer a noise or vibration to alert them, but in either case, would prefer to take the corrective action themselves.

A lane-departure warning system detects when a vehicle is drifting out of its lane without an activated turn signal. As with blind-spot alerts, the warning could be audible, visual, or physical as with a vibrating steering wheel. Consideration for this technology isn’t as high as blind-spot detection.

Currently the blind-spot technology has made its way to a few vehicles, such as the Buick Lucerne, Cadillac DTS and STS, Mercedes-Benz S-Class, and Volvo XC70 and S80. Lane-departure warning systems are available on some BMW, GM, and Infiniti models. Most manufacturers offer these technologies as an option and charge an extra fee. Appeal for these technologies in the survey dropped when consumers were made aware of the additional cost.

For more information on these and other future safety innovations, see our report on What’s next in auto safety. Also, read "Ignorance is BLIS."

—Liza Barth

Electric cars take charge in Israel, Denmark

When I attended the Electrical Vehicle Symposium 23rd (EVS23) last year, I wondered: After 23 symposiums, why are there still no electric vehicles to speak of? Does that mean a collection of scientists, academics, and government officials have just been talking about the subject since 1969, when the first EVS conference was held? It may seem that way on the surface. However, we've recently driven electric vehicles, some of which seemed almost ready for prime time. (Read our EVS23 report "Who revived the electric car?") Beyond those commendable vehicles, a few other developments are lurking behind the scenes.

For Earth Day, we thought it would be appropriate to highlight some of the ongoing projects that may advance the international electric car cause.

At the 2008 New York auto show, Mitsubishi showed the iMiEV an electric car based on the "i"—a rear-wheel-drive micro car that's sold in Japan. Subaru has a fleet of electric micro cars, called the R1e, that are used by the Tokyo Electric Power Company. Nissan is also testing an electric-powered version of its Cube - its home-market competitor to the original Scion xB. All three use lithium-ion batteries.

If any automaker is poised for real-world mass-market electric vehicle, it might be Nissan. Here's why: The alliance between Nissan and French automaker Renault will soon be selling electric cars in Israel. Renault has recently partnered with a Silicon Valley based Israeli start-up Project Better Place (PBP) to supply electric-powered Renault Megane sedans to be sold in Israel starting in 2011. PBP, in turn, will create a network of 500,000 battery charging and replacement stations throughout Israel, as well as charging points in public parking garages and along streets.

Israel seems an unlikely candidate to be the first county to adapt an electric car, where environmental causes are not generally considered a top priority. However, it is a country where driving distances are relatively short, which alleviates the main concern associated with electric vehicles' inherently limited range. In fact, 90 percent of car owners drive less than 44 miles a day and the country's three largest cities are within 100 miles of each other.

The electric Renault Megane, a sedan the size of a Volkswagen Jetta, is said to be able to accelerate from 0-60 mph in eight seconds and have a range of 125 miles. Purchase price is expected to be similar to that of an equivalent-sized car with a 1.6-liter engine, according to Carlos Ghosn, President and CEO of Nissan Motor Co. and Renault S.A., and Shai Agassi, CEO of Project Better Place. A generous tax subsidy by the Israeli government will help make the price of the car competitive.

Megane EV owners will subscribe to a battery replacement or recharging plan that's based on their mileage. An onboard computer will indicate mileage left and the location of the nearest battery replacement or recharging spot. Removing and replacing the battery is planned to be performed by a robot. Operating costs are expected to be significantly cheaper than filling up with gasoline. This is no surprise, as a gallon of regular unleaded costs about $6.90 in Israel.

A similar experiment is planned for Denmark, another country known for relatively short driving distances. In the Danish scenario, cars would be plugged in for recharging and that energy will be generated from renewable wind power. In Israel, most electric power comes from coal power stations; coal is neither a renewable source nor clean. Consequently, a mile covered by the electric Megane emits no CO2 compared to the 293 gram per mile for the conventional model, there would be added CO2 emissions at the power plant.   

The battery for the Renault is an advanced lithium-ion type, developed by Nissan and NEC of Japan. This type of battery is commonly considered the next step from nickel-metal hydride batteries used in today's production hybrids. Li-ion batteries are still considered by many experts to be in their developmental infancy for automotive use and concerns about its longevity, charging time, and potential to overheat are still being addressed.

When it comes to electric vehicles, it's hard to determine if the number of enthusiasts outnumber the skeptics. Nevertheless, such mass-market experience gathered in terms infrastructure, and especially in battery charging/replacement, may give Nissan a competitive edge. More importantly, it may significantly push the EV cause forward. If the Israeli and Danish tests prove successful, it would be only a matter of time until other markets take a serious look at the potential.

Hopefully, by the time EVS24 convenes in 2009, 40 years after the first EV symposium, even more promising electric vehicles will emerge.

—Gabe Shenhar

For suggestions on how to live more green, visit Consumer Union's Web site Greenerchoices.org and our Earth Day special section. For more tips on saving fuel and alternative fuels, see our fuel economy guide.

Discuss alternative-fuel vehicles in the forums.   

Earth Day 2008: Driving green

When it comes to driving, it's not easy being green, even on Earth Day. After all, we need cars to commute and run essential errands. Plus, as a nation, we love the freedom cars provide. But even providing for our work and family needs, there are ways to reduce the environmental impact from our motoring.  Besides buying a more fuel-efficient vehicle, here are some suggestions that can be applied today with your current vehicle:

Car pool: There are many companies that offer ride-share programs that match you with others in your area. Another option is to check with co-workers or friends in the neighborhood to see if they are going your way. Telecommute (aka work at home) if your company permits it. This will save both fuel and, another precious commodity, your time. When possible, go shopping with family and friends, rather than alone, and "chain" together multiple destinations into one trip.

Park it: Leave your car at home and take public transportation if available, or use a bike, walk, or roller skate for more local trips. The latter options will give you some exercise, too.

Get flexible: See if your employer will allow a flexible schedule, so you are not commuting during peak rush hour times. Also, run errands at off hours to avoid driving in congested traffic.

Lose weight: Remove unnecessary cargo from the trunk, such as salt, sand, or shovel left over from winter driving. Removing a roof rack, you can lighten your load, reduce drag, and aid fuel economy. For SUVs and trucks, remove (or avoid buying) heavy push bars and side steps.

Slow down: Drag rises with speed. Slowing from 75 to 55 mph boosted gas mileage 33 percent in testing performed on a sedan and in a large SUV.

What are you doing to be a greener driver? Share your experiences and tips in the comments below.

—Liza Barth

For more suggestions on how to live more green, visit Consumer Union's Web site Greenerchoices.org and our Earth Day special section. For more tips on saving fuel and alternative fuels, see our fuel economy guide.