Low-Emissions Vehicles Are the Dirtiest You Can Buy

How Low Is Low Enough?


  • Low-Emissions Vehicles

    Low-Emissions Vehicles

    Smog was painfully bad in the late 1950s and early '60s when car tailpipe emissions were unregulated. The next freeway sign was often hard to read through the petrochemical haze. | April 19, 2013

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Choosing a Low-Emissions Vehicle sounds like a prudent choice: a socially responsible move for a genuinely concerned consumer. An LEV is the one that discerning citizens should seek out and buy, right?

Not so fast, Mr. Begley, Jr.

As it happens, the Low Emissions Vehicle (LEV) designation is about as dirty as new cars get.

Classic Rewind
It wasn't always this way, of course. Back in 1965, cars had nothing in the way of pollution control equipment, and the average new automobile belched out some 2,000 pounds of smog-forming hydrocarbons every 100,000 miles.

In the 1960s and '70s the air in Los Angeles was often orange enough to make the next freeway sign hard to read through the petrochemical haze. It physically hurt to take a breath on smog alert days. In 1975 there were 118 Stage-1 smog alert days in Los Angeles.

Richard Nixon signed the Clean Air Act into law in 1970, setting the stage for automobile tailpipe emissions regulations, among other things. Pollution control technology evolved rapidly after that, with catalytic converters making their first appearance in the late '70s. But it wasn't until George H.W. Bush approved major revisions to the Clean Air Act in 1990 that the regulators really hit their stride.

LEV Tightens the Emissions Noose
California's Air Resources Board (CARB) rolled out an LEV program soon after, intended to cover model years 1994-2003. Low-emissions vehicles were the focus, so the LEV category key took center stage.

Don't let the name of the program confuse you, though, as it was not only called the LEV program, it also contained a category called LEVs. Get used to it; this is the government at work.

Despite its marquee status, the LEV classification itself was never seen as the end game, so the program included a more stringent category called ULEV or Ultra-Low-Emissions Vehicle. Before that there was even a weaker Transitional Low-Emissions Vehicle category (TLEV) that helped get the ball rolling.

The categories are fixed, but the manufacturers had to steadily certify a greater number of their products to higher categories each design cycle. The ULEV level is where the fleet average was intended to settle by the program's end in 2004. From the outset, the LEV emissions category was destined to sink to the unfavorable end of the spectrum as the decade-long program matured.

Even Tighter Restrictions
Automakers rose to the challenge. Midway through the program in 1998, the average new car was producing only 50 pounds of hydrocarbons over 100,000 miles. But it wasn't enough. Because the LEV program hadn't been particularly tough on oxides of nitrogen, commonly known as NOx, another round of emissions regulations covering the next 10 years was put in place to take advantage of promising new engine technologies.

A new program began in 2004 that redefined ULEV as LEV II and extended the emissions certification period from 100,000 miles to 120,000 miles. A stricter category, ULEV II was defined as well, but there was even a cleaner new category called — wait for it — Super-Ultra-Low-Emissions Vehicle or SULEV II. This ambitious classification was designed to limit hydrocarbon emissions to a single pound over 100,000 miles.

LEVs Are Dirty, Even Without CARB
All of the above applies to California, the District of Columbia and 14 other states that have signed on to the CARB regulations. Population-wise, it's a big group that represents nearly 40 percent of the market in terms of new vehicle sales. The other 35 states and 60 percent are governed by the EPA's "Tier II" program, which isn't quite as stringent and forgoes the superhero category names in favor of emissions "bins," which are numbered one through eight.

Tier II Bin 1 is for electric vehicles and Bin 5 is identical to CARB's current LEV II emissions classification, so in theory there are three federal categories that are dirtier than the LEV II level. But, increasingly, these are rarely used. As of 2009 some 92 percent of federally certified cars and 91 percent of pickups were classified Tier II Bin 5 or cleaner.

This means that even in federal emissions states, you'd be hard-pressed to find anything new on a dealer's lot that's dirtier than the LEV level. Only a handful of the largest heavy duty trucks and vans manage to creep above Bin 5. So once again, LEVs are essentially the dirtiest cars you can buy.

Why the difference between CARB and the feds? Primarily it's because CARB states face bigger smog problems, either through population density, topography or both. California's gasoline contains an average of just 10 ppm of sulfur instead of 30 ppm, and that difference makes the catalytic converter last longer and allows different emissions calibrations.

Why Cars?
CARB began taking a detailed inventory of statewide emissions in 1975. The so-called South Coast Air Basin was (and still is) the hot spot. This is the highly populated region of Southern California that butts up against the coast and is hemmed in by high mountains. Hollywood, Disneyland, Pacoima: it's all there.

Back then, on-road motor vehicles accounted for 58 percent of hydrocarbons, 90 percent of carbon monoxide (CO) and 59 percent of oxides of nitrogen (NOx) in the stinging orange air that millions of people in the region were breathing. Some 90 percent of each of those came from the tailpipes of passenger cars, light- and medium-duty pickup trucks and SUVs.

What about other sources? Stationary emitters like power plants, refineries and industry emitted 26 percent of the hydrocarbons, just 2 percent of CO and 18 percent of the NOx. Off-road mobile sources including ships, trains, aircraft, farm equipment, off-road industrial commercial equipment and recreational boats made up less than 8 percent of the hydrocarbons and CO and 19 percent of the NOx. We even compared a leaf blower to a couple of the latest cars and trucks to see how they stack up.

Clearly, big gains could be made by focusing on automobiles. But the other sources were addressed to varying degrees, too.

Where We Stand
By 2010, total emissions of hydrocarbons in the region had fallen from 3,200 tons per day in 1975 to 788 tons per day, a drop of 75 percent. CO fell 82 percent and NOx was reduced 56 percent over the same 35-year period.

Cars and pickups now accounted for 19 percent of the hydrocarbons, 20 percent of the NOx and 50 percent of the carbon monoxide.

Curiously, NOx emissions from heavy-duty vehicles increased 142 percent over the period, primarily due to heavy-duty diesel trucks. But these are currently on a downward trend from a peak a few years back due to recent efforts in that area.

The other standout is recreational boats and off-road industrial and commercial equipment. Emissions from the former have actually increased, while the latter hasn't dropped as much as other sources. Taken together, these now account for 16 percent of hydrocarbons, 30 percent of CO and 25 percent of NOx.

Cars are still one of the largest single sources, but the progress is staggering, to say the least.

Regulators Unite
Between 2015 and 2017, CARB standards and federal standards will merge. The number of states voluntarily signing up for the higher CARB standards has steadily increased, and automakers would rather not calibrate, certify and service two different emissions systems for different parts of the country.

The standards will tighten, especially on the federal side as it catches up to CARB. And there's additional focus on particulates and formaldehyde. California's 10 ppm sulfur standard for gasoline is set to roll out to all 50 states, and that opens the door for an increase in the certified life to 150,000 miles for each one of the new harmonized emissions system categories.

Like all previous programs, these new Phase III regulations will roll out gradually over the next several years as new generations of vehicles are designed and sold. By 2025, the horizon of the LEV III and proposed Tier III programs, the dirtiest vehicles on the road will be cleaner than today's Ultra-Low-Emissions Vehicles and the average will approach SULEV territory.

And then what: Mega-Hyper Super-Ultra-Low-Emissions Vehicle?

Shifting Focus
Unlikely. Increasingly, the focus is on CO2, a substance that wasn't considered a pollutant that could be regulated until 2007 when the U.S. Supreme Court decided that it met the definition of "air pollutant" described in the Clean Air Act.

CO2 emission regulations have already been drawn up and put in place, but they're not part of LEV III and Tier III because reductions in this greenhouse gas are only achieved through burning less fuel. That boils down to fuel economy and mpg, the realm of CAFE regulations, and that's another topic altogether.

And so the focus shifts, as well it should. LEV II has taken much of the sting out of the air, and the harmonized CARB and federal regulations should get all 50 states on the same page. Super-Ultra Low is probably low enough.

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