All About: Greener driving

By Rachel Oliver - For CNN

(CNN) -- A fact that may surprise people: the most recycled consumer product in the world is the car: 95 percent of all cars get recycled at the end of their lives, according to the U.S. Environmental Protection Agency (EPA).

(Picture: Smoke billowing out of a car's tailpipe. Clean car advocates would like to see these gone for good.)

Even though cars don't get recycled in their entirety -- as some materials are easier to recycle than others -- according to the American Council for an Energy-Efficient Economy (ACEEE), if you took an average car down to the local recycle yard, they could take 75 percent of it off your hands.

The reason cars are so environmentally unfriendly is basically due to the gasoline they burn. If you took the entire process that is involved in a car's average lifespan (from sourcing the materials, to manufacturing the car, to driving it, to eventually breaking it down for recycling) fuel would represent around 90 percent of that car's overall greenhouse gas emissions

America's oil addiction

Despite advances in the technologies surrounding cleaner cars, around 96 percent of American cars and trucks still rely on petroleum, needing 120 billion gallons of it every year, says ACEEE. Cars contribute greatly to the reason why the U.S. imports as much oil as it does -- around 20 million barrels every day (costing the country $1 billion daily) -- 40 percent of which goes straight into Americans' gas tanks.

America's oil-fueled cars play a disproportionately large role in the country's -- and the world's -- environmental ills, producing:

Nearly 50 percent of the world's auto-related greenhouse gas emissions
Nearly one quarter of all U.S. carbon dioxide emissions
Nearly two-thirds of U.S. carbon monoxide emissions
One-third of U.S. nitrogen oxide emissions
One quarter of hydrocarbons in the atmosphere
50 percent of all air pollution in the U.S.

The reason, environmentalists say, so much oil is set aside for cars is because they are not fuel- efficient enough. The fuel economy of American cars and trucks are now at a two-decade low -- the fuel economy of new cars and trucks back in 1987 was actually better than it was in 2004 (26 miles per gallon compared to 24.4 miles per gallon). Today it stands at around 25.3 mpg.

The last time strict fuel efficiency standards were imposed on U.S. auto manufacturers was in 1975 (it was also the first time) which called for 27.5 mpg within 10 years. That dropped to 26 mpg in 1986 following government lobbying by Ford and General Motors. The next time a new fuel standard would be set would be more than 20 years later -- at the end of 2007.

During that 20-year period, the Union of Concerned Scientists (UCS) has accused automakers of having "increasingly exploited loopholes in Congressional and regulatory language" and has accused the U.S. government of having "turned a blind eye to them or made them larger."

Auto manufacturers for example, have been allowed to reclassify minivans, sports utility vehicles (SUVs) and station wagons and certain cars as non-passenger vehicles, "thereby qualifying them to meet a lower fuel economy standard". And some vehicles have been exempted from fuel economy standards altogether.

Last year's U.S. Energy Bill stipulates that cars must improve fuel efficiency standards by 40 percent to reach a fuel efficiency standard of 35 mpg by 2020. UCS says that's not enough and wants fuel economy standards in the U.S. to reach 40 mpg by 2015 and 55 mpg by 2025. Doing that would "save three times more oil...than we could recover from the Arctic refuge" it says.

Automakers say incentive is needed

Auto manufacturers have tried to argue in the past that as long as petroleum remains cheap, consumers have no incentive to buy more fuel-efficient cars --which means they don't have the necessary incentives to build them.

That argument may not hold for much longer. At the beginning of 2008, the price of oil hit $100 a barrel for the first time and is now five times more expensive than it was at the start of 2002.

And that, The Economist pointed out in a recent leader, has been more down to politics than the lack of supply. Yes, there is a finite amount of oil for the world to drill -- but the real problem is where it is. Unless the likes of Exxon Mobil and Shell are given unfettered access to the likes of Iran or Venezuela's vast oil reserves any time soon, for instance, prices are going to stay where they are (or go higher still).

"The economic toll of expensive oil is just as high whether geology or politics is to blame," the Economist wrote. "And the best response is just the same. Policy should encourage energy efficiency and support research into alternative fuels."

All eyes on hybrid cars

In order to slash oil dependence, much attention of late has been given to the hybrid car.

Currently, hybrid gas-electric vehicles represent around 2 percent of the U.S. passenger car market, ENN reports. A recent study by the Electric Power Research Institute (EPRI) and Natural Resources Defense Council (NRDC) suggested that with 20 percent market share, hybrids could slash greenhouse gas emissions by 180 million metric tons a year.

With 60 percent market share, it would be as much as 450 million metric tons -- the equivalent of taking 82 million cars off the road (a third of all cars on American roads). It would also save the country between 3 million to 4 million barrels of oil a day, "more than twice what the United States imports each day from Saudi Arabia," reports the San Francisco Chronicle.

Hybrids still use gasoline which means less fuel economy than, say, electric cars, which don't need fuel at all, or plug-in hybrids which can draw energy from the electricity grid. Neither cars are widely available yet -- in the U.S. anyway. (Hint: if you want to see what energy-efficient cars really look like, visit Norway or Sweden).

With patience and money, hybrid owners can convert their existing hybrids into plug-in hybrids, to further minimize the fuel they are burning. According to UCS, using existing "off-the-shelf technologies" motorists can "affordably and safely boost fuel economy by nearly 75 percent."

However, "affordable" is a relative term. If you live in California, for example and want to convert your Prius into a plug-in hybrid, it could cost you between $10,000 and $12,000 to install the extra batteries according to CNET, which points out, "at that price and with gas at $3 a gallon, it would take around 160,000 to 200,000 miles of driving to break even."

Efforts are under way, however, to create DIY open-source style conversion kits which could sell for as less as $3,000. The California Cars Initiative (CalCars) is aiming to have a kit ready by this summer, according to CNET, although as it will be a volunteer-based effort, that deadline is not guaranteed by any stretch.

The need for fuel-free cars

The best kind of fuel efficiency is no fuel at all. But simply taking oil out of the gas tanks does not solve all environmental problems.

The Reason Foundation for example, recently released a report saying that hydrogen cars are no panacea for the transportation problem. If anything, widescale implementation of hydrogen cars -- along with the necessary infrastructure to support them -- could actually boost CO2 emissions.

The reason? A "significant" amount of energy is needed to produce and move around the hydrogen that is needed in the first place. Furthermore it increases reliance on foreign-produced natural gas, the report adds. And the parts of the world with this biggest gas reserves with the exception of Russia are all in the Middle East.

We are quite a way yet from solar-powered cars, which still have to get past the issues of speed and load capacity (the heavier the vehicle, the slower you go). So that leaves the electric vehicle (EV).

The first EV took to the streets in 1834, a creation of Vermont-native Thomas Davenport. In that same century, a gentleman named William Morrison built an EV that could travel non-stop for 13 hours (admittedly at 14 miles per hour). And by 1900, an EV could go 180 miles on one fully-charged battery.

At its peak, in 1912, the EV industry had 35,000 vehicles on the road in the U.S. alone. Nearly a century later, many argue that they are still our best bet.

Efforts by the likes of GM to introduce EVs into the market in the 1990s floundered -- car makers said it was because of a lack of customer demand. It is doubtful they could argue the same point today.

EVs don't need fuel to power them, which means no tailpipe emissions. But 'no fuel' doesn't mean 'no problem'. Your average EV owner needs to plug into a grid to charge up. And depending on what kind of fuel powers that grid ultimately decides how environmentally-friendly the car actually is. That has led the likes of Toyota recently to suggest EVs are not appropriate for the Chinese market -- because it's electricity grid is powered by coal.

But even if the grid is 100 percent coal-powered, argues, the overall CO2 emission savings still mean all EVs are a better bet environmentally than anything else on the road.

On average, cars emit 22 pounds of C02 (as well as other pollutants) for every gallon of gasoline consumed. An EV's CO2 emissions will come from whatever fuel is powering the grid it's plugged into. Assuming the grid is 100 percent coal-powered, and say the journey is 25 miles (which your average tank of gasoline will take you), then an EV will consume around 5 kilowatt hours (kWh) of electricity at 200 watt hours per mile, to get there, using up around 5 pounds of coal.

On average (depending on the type of coal used) 1 kWh produces 1.4 pounds of CO2 which would mean a 25-mile journey using 5 kWh would emit around 7 pounds of CO2 compared to your average vehicles emitting 22 pounds of C02.

As more types of renewable energy sources become more mainstream, grid-related emissions will drop even further. Equally some electric vehicle owners have been able to recharge their cars with solar panels, which means their emissions are practically zero (although the emissions involved with actually constructing the solar panels and the cars will mean that no cars are ever totally clean).

Issues remain with electric cars

There are issues still to be resolved with EVs. Overpowering the grid has traditionally been one of them. The environmental impact and safety record of the batteries is another.

On the first point, electric drive proponents point out that as most car owners would plug in and charge their car overnight, while demand is low, the strain on the grid would be negligible. The EPRI/NRDC study appears to support this, suggesting that even if 60 percent of cars on America's roads were plug-ins, it would only lead to increases in electricity usage of between 7 percent and 8 percent.

As for the issue of batteries, that may take some time to solve. Despite GM's planned EV comeback in 2010 with the Volt, heralding the return of mass-market players to the EV scene, the Wall Street Journal reports it "still hasn't solved the battery problem".

The problem being, it says, "how to make a small enough battery that will hold a big enough charge for these new cars -- and not be a risk to burst into flames". Specifically it is referring to lithium-ion batteries, which U.S transport authorities have cracked down on (loose ones in checked luggage are no longer allowed on planes, such is the level of concern of them exploding) following reports of lithium-ion batteries used in laptops and mobile phones overheating and bursting into flames.

According to the Journal, Toyota was going to use lithium-ion batteries in its new Prius, but shelved the idea (until at least 2010 at least) due to safety problems. There are a couple of players on the market however, who say they have got round the problem, one of them being laptop maker Toshiba.

But perhaps an even more environmentally-friendly car than the EV is the Air Car, which is an Indian invention. The Air Car runs on nothing but compressed air and can be easily filled up at any gas station. All the car needs is 320 liters of air, which will cost Indian consumers around $2, according to Popular Mechanics.

If consumers don't want to even pay for that, they can plug their car into the local grid and an in-built air compressor will do the job in 4 hours. Air Car is due to launch in India this August and 12 countries including Germany, Israel and South Africa have placed orders with Air Car's manufacturer Luxemboug-based MDI.