Getting Around Greener Part 5

About this series: As a BTG supporter, you understand that our transportation choices have tremendous ecological impacts, but you may not be aware of the latest innovations and improvements in your options. With this series, we hope to help you find new ways to both lower your individual impact now and move us all toward a sustainable transportation system ASAP. Please send us any additional suggestions you have.

In Part 1, we looked at options for getting around without a car at least some of the time as well as how some of us may even be able to avoid owning a car entirely.

In Part 2, we looked at how to drive greener when you do and what to consider when trying to decide whether to keep your current car or buy a new one.

In Part 3, we considered the impacts of driving a plug-in car.

In Part 4, we explored some of the obstacles to electrifying our car culture.

Now, in Part 5, we delve deeper into the benefits of driving the right-size car.

In Part 2, we briefly mentioned the importance of right-sizing the car you drive That means choosing a vehicle that has the passenger and cargo capacity you need frequently and renting or borrowing a vehicle on those occasions you need more. Now we thought we’d put this in concrete terms by using a real-world example.

Honda’s Civic sedan and CR-V crossover are among the best-selling vehicles in their respective classes. They share their underlying modular platform, which refers to the major mechanical and structural components of the car. This includes an optional turbocharged engine, though the version in the CR-V has been tuned to produce more horsepower because it’s a larger, heavier vehicle – more on that later.

The Civic sedan and CR-V have comparable passenger capacity with seating for five. The CR-V does have a bit more head, leg, shoulder, and hip room.

How do they compare in fuel-efficiency? When equipped with the most efficient powertrain combination, the Civic sedan is rated at 32 City/42 Highway/36 Combined. In contrast, the most-efficient 2WD version of the CR-V is rated at 28/34/30. The most-efficient AWD version is rated at 27/33/29, but we’ll focus on the 2WD version because there is no AWD Civic available.

This should come as no surprise. First, the larger body of the CR-V add considerable weight, with the Civic weighing around 500 lbs. less depending on the trim selected. The more weight the engine has to haul around, the more energy it needs to use.

The shape and higher ride-height of the CR-V also makes it significantly less aerodynamic than the Civic sedan. This increased wind resistance requires the engine to use more fuel to propel it, particularly at higher speeds.

Now, according to the most recent data from the National Highway Administration, Americans on average drive 13,476 miles per year. As a BTG supporter, let’s assume you drive less than the average, a nice, round 10,000 miles/year. A Civic averaging 36 MPG year-round would burn 278 gallons of gasoline to drive 10,000 miles. In contrast, a CR-V averaging 30 MPG year-round would burn 333 gallons – a difference of 55 gallons.

That’s 55 gallons of gasoline you wouldn’t have to buy, saving you money, of course, though not a huge amount. It also means the oil that would have to be extracted and refined to make the gasoline, with all the pollution that entails, wouldn’t be needed.

It’s also 55 gallons of gasoline that wasn’t burned, producing smog-forming air pollutants (nitrogen oxides and hydrocarbons), particulates, toxic air pollutants like benzene, carbon monoxide, and, of course, carbon dioxide (CO2), the principal greenhouse gas.

And just how much CO2 does 55 gallons of burned gasoline produce?

According to the US Energy Information Administration, every gallon of gasoline (assuming no ethanol) burned produces about 19.64 pounds of CO2. If we multiply 19.64  times 55, we find you would avoid emitting 1,080 pounds of CO2 into the air every year you drove the Civic rather than the CR-V.

If you kept your car for 7 years, that would be 7,560 pounds of CO2  kept out of the atmosphere.

Perhaps you really like or need the utility of a hatchback, however. Fortunately, Honda has begun offering a Civic hatchback in the US for the first time in years, though it’s not quite as light as the sedan, nor as aerodynamic. Those two factors reduce the fuel economy of the most-efficient version to 31 City/40 Highway/34 Combined.

Consequently, a Civic Hatchback getting 40 MPG Combined would use 294 gallons of gasoline to drive 10,000 miles over the course of a year. That’s 39 gallons less than the 333 calculated above for the most-efficient CR-V. Burning those 39 gallons would put about 766 lbs. of additional CO2 into the atmosphere over one year and about 5,362 lbs. over seven.

Of course, some people genuinely need the utility offered by a crossover on a frequent basis, and some need all-wheel drive capability. Fortunately, an increasing number of hybrid crossovers are now on the market, which you can read about in our earlier post, “High-Ridin’, All-Wheelin’ Hybrids.”