It's one thing to drive a vehicle that's called "eco-friendly" - it's another to actually know why and how said vehicle is better for the environment than the one your neighbor is driving? Do you know what the difference is between a hybrid and a plug-in electric vehicle? Don't feel too bad if you don't because you're far from the only one.

Here's a brief rundown of the what's what in environmentally-conscious vehicles so the next time someone asks you your thoughts on the low-emission trend, you can nod knowledgeably and add your two cents to the conversation. Or even better, make a green choice should you be in the market for a new set of wheels!

Plug-in electric
Plug-in electric vehicles have no emissions thanks to an internal combustion engine that does not require the use of a gasoline-powered engine. Instead they use battery packs and energy from your local grid, but do not require the frequent trips to a local station or the accompanying oil changes of a more traditional vehicle. Nor do they have the fuel tank and other components of the car you are probably used to driving. Instead you simply plug your vehicle into an electrical outlet, much the way you would with your cell phone that requires recharging.

Though electric cars have no fuel emissions to consider, they do consume electricity and should the demand for the vehicles ever be great enough, could significantly increase the demand for electricity.

Hydrogen-powered
A hydrogen-powered vehicle may be one of the most eco-friendly of all - a vehicle that runs on clean water with absolutely no carbon emission. But is it realistic? Experts say not yet, though there is a push to make it happen. The BMW Hydrogen 7 version of a hydrogen vehicle has been a hit with celebrities like Brad Pitt, Angelina Jolie and Kristen Davis, while America Ferrera (aka Ugly Betty) has been rumored to be a fan of the Chevrolet Equinox Fuel Cell. However, the fact remains, the high costs of manufacturing fuel cell vehicles and the lack of infrastructure to actually support them.

In a car with a hydrogen internal combustion engine, the hydrogen burns the same was as the fuel does in a traditional vehicle. In a hydrogen fuel cell vehicle, the reaction between hydrogen and oxygen produces water and electricity to power an electric traction motor.

Solar-powered car
This type of vehicle almost explains itself. Much the same as solar panels work to power a home, they work to provide power to a car. These panels are used to generate electricity by converting sunlight into energy. Because sunlight is already used to provide heat and electricity to homes, some hold onto the hope that they can revolutionize the auto industry.

Currently solar cars are mostly built as an experiment by teams in a competition, not as viable vehicles to be purchased on a lot by consumers. These cars use different types of batteries in its electrical system including lead-acid batteries, nickel-metal hydride and Lithium ion batteries. 

Hybrid
Hybrid vehicles use two sources of power, such as the internal combustion engine you would find in a traditional vehicle with a rechargeable system such as a battery or an electric motor. Hybrids are not just limited to the production of cars, but include SUVs, trucks and even buses.

The two sources used in hybrid vehicles is rapidly expanding to include plug-in hybrids, diesel-electric hybrids that rely on bio diesel and even hydrogen fuel cell hybrid.

Fuel-efficient
These vehicles don't technically classify as one the green cars as they do not necessarily utilize any of the aforementioned technology. Instead these vehicles are "traditional" ones that get great gas mileage and have reduced emissions.

It also turns out the even the newer cars don't always equal the best; often times older models of some cars get more miles per gallon. The 1996 Geo Metro XFI for example, achieves the same number of miles per gallon as the Toyota Prius, however without the recent manufacturing process to factor in.

» Plug In America

It's no huge surprise that information available on the Internet about green cars is somewhat scattered. After all, alternative fuel vehicles (AFVs) are part of an emerging market  and up until a few years ago, a green car usually described the paint job on a vehicle as opposed to its eco-friendly characteristics. However with nearly 70 models available and 11 million vehicles on the road, the AFV industry has taken on a life of it's own. Ken Snoke was aware there were gaps in the information about environmentally-conscious vehicles and it was this realization that inspired his idea for a single location online where people could conveniently research, as well as buy and sell green vehicles.

GreenCarDepot.com specializes in alternative fuel vehicles - that is, any vehicle that does not run exclusively on gasoline - and divides them into easy-to-find categories including hybrid, ethanol, biodiesel, electric, hydrogen, and compressed air. This breakdown allows buyers to easily research the type of vehicle they are searching for and if the exact vehicle isn't available at that time, a free email alert will notify the buyer when one is. The site also has sections for industry-related parts and even careers.

Check out GreenCarDepot after the jump.

» Green Car Depot

There's something new rolling along the highways of Massachusetts - well more accurately, several new things. This past week, Coca-Cola Enterprises deployed 15 hybrid electric delivery trucks at the Needham Market Service Center, the largest single deployment of hybrid vehicles in the company's history.

The new trucks include 10 hybrid electric tractor trailers, three hybrid electric 12-bay box trucks and two hybrid electric cooler delivery trucks. Not only are the tractors the biggest hybrid electric trucks in North America, they use 30 per cent less fuel and produce 30 per cent few emissions than standard delivery trucks. The vehicles will be used to deliver Coca-Cola products in the metro Boston area. And the company isn't done yet - by the end of 2009, they will deploy a total of 185 electric trucks, bringing their fleet to 327 hybrid delivery trucks, the largest in North America.

“These hybrid trucks are a strong example of how we’re delivering on our Corporate Responsibility and Sustainability commitments,” said Steve Cahillane, president, Coca-Cola Enterprises North America.  “We have set aggressive targets and goals related to energy conservation / climate change and water stewardship, and activities like these will help us meet these goals.”

The vehicles aren't the only eco-friendly initiative undertaken by the Needham center. The facility also features energy-efficient lighting that saves more than 1.5 million kilowatts of energy each year, as well as water-saving technologies including condensation pumps and air rinsers, which conserve more than 4.5 million gallons of water on an annual basis.

Massachusetts Energy and Environmental Affairs Secretary Ian Bowles was on-hand this week to introduce the new trucks and believes Coke is setting a good example that demonstrates just how much good a large corporation can do.

“By investing in hybrid technology that decreases tailpipe emissions and reduces our dependence on foreign oil, Coca-Cola Enterprises is distinguishing itself as a clean energy leader,” said Sec. Bowles. “Today's announcement that the company is deploying 15 hybrid trucks is good news for the Commonwealth's environment and for our clean energy goals, and we commend Coca-Cola’s decision to go a step further by committing to the Department of Energy Resources’ Clean Cities application for 20 additional hybrid trucks as part of our proposal to fund over 300 highly efficient vehicles in Massachusetts through the federal stimulus package.”

» Coca Cola (Official Site)

Back in September, photos of the new Chevy Volt were leaked online and now conveniently it's supposedly Toyota's turn. The 2010 Prius isn't supposed to be officially unveiled until January 2009 at the North American International Auto Show, however new photos have appeared on the Internet...kinda, maybe, sort of.

This is either a preview of what is to come, or could possibly just be a rejected makeover design of the current model. Or the third possibility being tossed around is that someone is bored and good with Photoshop.

The car shown integrates a number of current Toyota F1-inspired design cues such as the deep front valance with wide air foil-like air inlet and badge-capped protruding proboscis that extends up over the hood, mimicking the fuselage of the racing car. The recessed vertical fog lights also follow the brand's latest styling trends, while the Maxima-esque headlamp clusters are particularly creative.

Um yeah, what he said. Casting doubt on the legitimacy of the photos is the fact that this "new" car bears a striking resemblance to the current Prius except for the changes noted above. Experts are expecting a dramatic overhaul rather than mere upgrades to what already exists.

So is it or isn't it the new Prius? If it is, does it live up to the hype or a bit of a letdown? Tell us what you think and in the meantime, stay tuned!

» Driving.ca

Honda is prepared to compete with Toyota and their number-one selling Prius and will sell their new gas-electric hybrid at a lower price. Expected to launch next April, the new five-door vehicle will only be available as a hybrid car and will be smaller and less expensive than the Honda Civic.

Honda already has the most fuel-efficient vehicle models in the U.S. but has yet to release details regarding the new hybrid's fuel economy. To beat the Prius, the Honda car will have to get more than 48 miles per gallon in the city and 45 miles per gallon on the highway. Executive vice president of the U.S. chapter of Honda, Richard Colliver says that the company has set sales targets but will not necessarily try to outsell the Prius.

“We’re targeting sales of 100,000 units of this new vehicle in North America,” he said in a speech at the Center for Automotive Research Management Briefing Seminars.

The new vehicle will be sold in the U.S., Japan and Europe in early 2009.

» MSNBC Environment

Not all green cars are created equal, however several models do have one important aspect in common: their release year. As the competition to become the leader in a growing industry intensifies, several manufacturers have decided to introduce eco-friendly vehicles in 2010. This is a race in which nobody wants to be left behind, so auto makers are doing their darndest to make their new offerings as appealing to the masses as possible. Among the vehicles set to debut that year are:

Chevrolet Volt - The Volt has been generating a respectable amount of buzz for awhile now and will attempt to give the Prius a run for its money in the plug-in hybrid market. The car will be able to travel for 40 miles before the gas engine kicks in, though its price tag is expected to be higher than originally thought.

Mercedes - Pick a model. The makers of Mercedes vehicles are clearly feeling ambitious, as they have announced their intent to eliminate petroleum-run cars from their lineup by 2015. Electric cars, hydrogen vehicles and biofuels are all expected to be developed and yes, the company also has plans to release an electric car in - you guessed it - 2010.

Nissan - Charles Ghosn, CEO of Nissan and Renault, has said Nissan will also introduce an electric vehicle to the U.S. and Japan in 2010, to which he added that the company hopes to begin "mass marketing zero-emission vehicles."

BYD - The Chinese battery maker wants to expand into hybrid cars and electric cars, first in Europe and then to the U.S., most likely with their plug-in hybrid, the F6DM, which has the ability to run for 62 miles before a small gasoline engine kicks in. The company is also expected to introduce the smaller version of their car, the F3DM, as well as the E6 electric car, similar to the F6DM but 100 per cent electric. BYD expects the car battery will have a lifetime range of 600,000 kilometers.

» The Huffington Post