Hybrid Watchdog: Do Hybrids Go the Distance for Vacation Travel?

For a number of years now, hybrids have been considered the keeper of the crown when it comes to environmentally friendly passenger cars. The high fuel economies and low tailpipe emissions of the most popular hybrid models have made the technology synonymous with eco-friendly engineering. While that’s not always the case it is true that today’s most popular hybrids are among the most environmentally friendly vehicles now on the road.

Efficient hybrids, such as the Toyota Prius, have earned their right as environmental darlings of the passenger car market. So if you’re planning a vacation, should you hop in your hybrid and hit the road? What about other modes of travel? How do efficient hybrids compare to, say, planes, trains, or buses? And do other factors matter, such as how many people are going or how far you’re traveling? This issue of the Watchdog gets to the bottom of those questions by parsing out some of the results from the recent UCS report, Getting There Greener: The Guide to Your Lower-Carbon Vacation. As you’ll see, the answers may not always be what you might expect.

Tale of the Tape
So, how do efficient hybrids stack up against the competition on a 500-mile or longer trip? In short, if an efficient hybrid car is used to move a family of four, it’s the most eco-friendly travel option around. For trips with only two travelers, hybrids are still a pretty good option, coming in second only to buses. But, for solo trips efficient hybrids fall down to the middle of the pack—especially on longer-distance trips where lower-carbon options exist such as the bus or train. And, perhaps surprisingly, a direct coach flight is a better travel option than driving solo in a hybrid if the trip is longer than 500 miles. The charts below, from Getting There Greener, show graphically how efficient hybrids compare to the other modes analyzed in the report.

Cars
To figure out where all this data came from, let’s first look at a typical car: a 23 mpg gasoline-powered sedan. Including “upstream” emissions (the emissions associated with the extraction, refining, and transporting of the fuel from the well head to the gas tank), the production and consumption of a gallon of fuel produces approximately 25 pounds of carbon dioxide (CO2) emissions. For a 500-mile trip, that amounts to 540 pounds of CO2 pollution. An efficient hybrid, such as the 46-mpg Gen. 2 Prius, would be half of that at 270 pounds.

When it comes to cars, however, that’s only part of the story, because the fuller a vehicle, the more environmentally friendly it is. On a per-passenger basis, a car with four seats occupied is roughly four times more environmentally friendly than it is when the driver travels alone. Accounting to the slightly lower fuel economy you get with a full vehicle, the per-person emissions for a family of four in the hybrid example above are a mere 75 pounds per passenger. Compared with other modes of travel, family trips in efficient cars offer considerable eco-opportunity.

Speaking of other modes, as Getting There Greener explains in detail, the lowest-carbon mode of travel actually does depend how far you’re traveling and how many people are going with you. While we’re only going to touch on some of the key findings in this Watchdog, detailed information about plane, train, automobile, and bus emissions is available in Getting There Greener, free online at the Union of Concerned Scientists web site.

Airplanes
The amount of carbon dioxide emissions from an airplane trip depends on numerous factors, including the type of plane(s) flown, how many layovers are taken (since takeoff and landing activities have their own sets of emissions), and how many miles are ultimately logged in getting to your final destination (which is affected by how far out of the way any layover stops might be). Another important factor that affects the eco-impact of plane trips is what class you’re traveling, since first class seats take up more room onboard and are therefore responsible for a greater share of the flight’s total emissions.

A 500-mile plane trip (non-stop, coach) emits slightly more than 300 pounds of emissions per passenger. However, additional family members don’t get the added emissions benefit that they do in personal vehicles, so a family of four making that trip amounts to roughly 1,200 pounds of CO2 emissions.

Buses and Trains
While they are often overlooked when it comes to vacation travel, buses and trains can also make great sense from a carbon perspective, as they are among your lowest-emission options, especially on shorter (less than 500-mile) trips. Per-passenger emissions from a 500-mile trip in a bus or train amounts to 84 and 215 pounds of CO2, respectively. Moreover, unlike planes—which have much higher occupancy rates—motor coaches and trains are often underused and may offer what amounts to a carbon “free ride.”

Daily Driving
Of course, even if it makes sense to leave your hybrid home when heading out on vacation, that’s no reason to stick with a gas guzzler over a hybrid for your daily driving needs. If you need a car, purchasing an efficient hybrid is a good choice. And if a hybrid is not available in the type of vehicle you need, always look for the highest fuel economy model that meets your needs.