America’s Lowest Carbon Footprint Cars

Do you ever wonder whether it matters for the environment what kind of car you drive?

According to the U.S. EPA, a plug-in hybrid like a Ford Fusion Energi can save 7,000 pounds of carbon dioxide (CO2) tailpipe emissions per year compared to a 26-mpg non-hybrid Fusion, or enough to plant 79 trees.

This is based on 15,000 annual miles, the trees are just a theoretical way to offset the greenhouse gases (GHG) released.

Not to pick on Ford, the Fusion Energi was chosen because it’s mid pack on the list excluding zero-emission battery electric cars – and the non-hybrid Fusion is close to today’s over 24-mpg average fuel efficiency rating.

Nissan's Leaf is the global best-elling plug-in car, and as a battery electric, has one of the lowest carbon footprints.

Nissan’s Leaf is the global best-selling plug-in car, and as a battery electric, has one of the lowest carbon footprints.

To be sure, better or worse comparisons could also be made but this is just to illustrate a point:

One person can make a difference with a car choice, and it’s not that hard to figure out with free online calculators the U.S. EPA provides – but we get you started here.

Despite Coal, Electrified Vehicles Are Cleaner

With the advent of hybrids, plug-in hybrids and battery electric vehicles, automakers themselves now have choices to produce products fit for emissions standards their entire fleets will have to pass by 2025.

These cars are ahead of the curve, but while the opening Fusion versus Fusion example taken straight from EPA numbers looks like an open-and-shut case, we must disclose actual performance may be worse or better.

BMW i3. Of course there are myriad other reasons why electrified vehicles exist – such as for energy security, because they are a neat-driving alternative, potentially lower maintenance, and more.

BMW i3. Of course there are many other reasons why electrified vehicles exist – such as for energy security, because they are a neat-driving alternative, potentially lower maintenance, and more.

A Fusion Energi rated at 129 g/mile GHG at the tailpipe is based on very averaged assumptions and it actually can operate at 0 g/mile for 19 miles, or with battery depleted it may emit a little more than a 209 g/mile Fusion Hybrid.

Nor do these tailpipe calculations account for “upstream emissions” – for electricity or gasoline.

While studies that cherry pick data have been presented to expose the alleged boondoggle of cars plugged into coal-intensive grids, also true is gasoline does not miraculously appear at the pump having bubbled freely from the ground like spring water.

Actually, there are “upstream emissions’ for electricity or fossil fuels, the EPA acknowledges this, and we won’t even get into myriad costs like guarding the Strait of Hormuz, the Persian Gulf War, and other environmental consequences from fossil fuels.

Tesla is the leading plug-in seller this year. The company does not believe hybrids are a good solution, and eschews gasoline. According to the U.S. Energy Information Administration (EIA), burning one ethanol-free gallon of gasoline produces about 19.64 pounds of CO2. One gallon of diesel yields about 22.38 pound of CO2 but diesel engines usually offset this by yielding increased fuel economy.

Tesla is the leading plug-in seller this year. The company does not believe hybrids are a good solution, and eschews gasoline. According to the U.S. Energy Information Administration (EIA), burning one ethanol-free gallon of gasoline produces about 19.64 pounds of CO2. One gallon of diesel yields about 22.38 pound of CO2 but diesel engines usually offset this by yielding increased fuel economy.

Keeping it simplified to look at the electric grid, upstream emissions can be estimated by zip code on an EPA calculator. According to it, our 129 g/mile Fusion Energi rises to:

• New York City: 220 g/mile
• Wheeling, West Virginia: 290 g/mile
• Marysville, Ohio: 290 g/mile
• Long Beach, California: 230 g/mile
• Kent Washington: 230 g/mile

The EPA calculator is not perfect, but it’s a guide updated regularly that while still including assumptions that may not apply to some, does help get closer to reality.

And, according to it, the Fusion Energi wins even in Dallas, Texas where its 270 g/mile tailpipe-plu-upstream emissions are cleaner than the regular Fusion which is 338 g/mile nationwide.

EPA's calculator is a guide to drill down on emissions.

EPA’s calculator is a guide to drill down on emissions.

But the 338 g/mile for the gasoline-burning Fusion assumes zero upstream emissions for its gasoline, and that’s not fair, is it?

No, and the EPA estimates another 80 g/mile for upstream gasoline emissions, so apple for apple, it’s 418 g/mile for the non-hybrid Fusion vs. 290 g/mile for the Fusion Energi plug-in hybrid.

Visualizing CO2

Invisible CO2 may be hard to imagine, but according to the Natural Resources Defense Council, if we were to dye it a brown, we’d see whiffs of brown stuff coming out of tailpipes.

pilates-stability-ball1

Not only does 6.3 pounds of gasoline produce an outsized 20 pounds of CO2, the gas itself is expanded and each pound would fill a 2.5-foot diameter rubber exercise ball.

On a given day, the tailpipe of a plug-in Fusion could fill 11.5 exercise balls, and a non-hybrid Fusion would fill 31. Factoring upstream emissions, the plug-in Fusion still holds a clear advantage.

There are 253 million cars and trucks on the roads, many emit far more than our relatively clean new examples, and can you imagine the sky filling up with all the exercise balls?

If we could see it that way, it could be like the sky is one of those kid’s playground attractions just filled with colored rubber balls jumbled together.

The Chart: lowest carbon footprint cars

Every year America’s regional electric grids get cleaner, meaning upstream emissions decrease annually. The same cannot be said of gasoline and diesel.

Based on EPA data, the chart presents all battery electric cars sold in the U.S., and most plug-in hybrids. We omitted a couple plug-in hybrids that emit more than regular hybrids as the subject is the lowest GHG cars.

The battery vehicle chart’s hierarchy is by tailpipe-plus-upstream emissions, as all cars have no tailpipe, and are zero. The plug-in hybrids and hybrids are in order of lowest tailpipe emissions to highest.

For electrified cars, the question of upstream grid emissions only applies to battery electric and plug-in hybrids as regular hybrids generate their own electricity onboard. Non-plug-in hybrids do however have upstream emissions from gasoline.

We used a Southern California reference for the “grid,” but as you know, this varies.

California is where 50 percent of the plug-in vehicles were sold last year, and its grid is at a level others are aspiring to meet.

You’ll note due to peculiarities in the EPA’s data, algorithms, and varying efficiency of blended gas-plus-electric powertrains that some PHEVs that do better at the tailpipe do not show superiority when upstream emissions are factored in.

Click chart to expand.

Click chart to expand.

As a benchmark to compare the electrified cars to, we arbitrarily picked a 25 mpg Honda Civic with 352 g/mile tailpipe emissions and 435 g/mile tailpipe plus upstream emissions. The EPA’s latest preliminary values for a national average new car sold in the country is 24.2 mpg and 367 g/mi – tailpipe-only – for 2014, and cars keep getting cleaner.

If you’re interested, other popular vehicles emit much more GHG. Just at the tailpipe, you have the Ford F-150 with 3.5-liter V6 at 471 g/mile, or 16,600 pounds per year, the Honda Odyssey at 402 g/mile or 13,200 pounds annually, four-cylinder Toyota Camry at 317 g/mile or 10,400 pounds per year. You can look them up yourself at fueleconomy.gov.

You may also note on the chart the EPA says, according to its drive cycle a Prius hybrid emits just 18 g/mile more than the Chevy Volt, and beats the Cadillac ELR by 12 g/mile when factoring tailpipe plus upstream.

The 2016 Chevy Volt is expected to surpass the 2015 with greater efficiency and 50 miles electric range.

The 2016 Chevy Volt is expected to surpass the 2015 with greater efficiency and 50 miles electric range.

But caveats apply double to plug-in cars. These are based on EPA assumptions and a tame drive cycle that assumes a certain percentage of gas and electric. Many Volt drivers decimate these numbers by using the battery far more to drive the car than an average government cycle.

Does that mean it’s false? No, under certain circumstances, if one matches the conditions the EPA works under which attempt to approximate normal driving, then your results could be close to spec.

Of course also, there are many other reasons for these cars than just carbon footprint, but this data is here for those who want to know about their relevance to climate change.