NEW YORK (MainStreet) — Spring is in the air and Earth Day is less than two weeks away, so here's an eco-friendly look at five cars the American Council for an Energy-Efficient Economy recently named as 2015's "greenest" models.

"The toll that cars and trucks take on the environment is often hidden but always very real ... unhealthy air pollution, oil spills and fouling of water supplies, damage to habitats and global climate disruption," the council wrote in its 18th annual Greener Car rankings. "If you care about the environment, then what you value goes beyond performance or styling and the options featured in the showroom."

The council's study aims to quantify different cars' total pollution output during their entire life cycles, from the smog created in building a vehicle to the tailpipe emissions created when you drive it.

Electric cars took four out of five top spots in this year's rankings, even after the council factored in pollution involved in building the vehicles' batteries and generating the electricity to recharge them.

Council researcher Shruti Vaidyanathan says electric cars scored well due to their high energy efficiency, low vehicle weight (which reduces manufacturing-related pollution) and the fact that electric-power generation typically creates less pollution than burning gasoline does.

"Small, high-efficiency electric vehicles are what we see at the top of the list," she says.

Vaidyanathan says such vehicles not only help the environment, but can put some extra "green" in your wallet by reducing fuel costs — although the higher sticker prices that some vehicles carry can reduce or even negate your savings.

John O'Dell, senior editor for green cars at auto-shopping site Edmunds.com, says electric models typically cost $10,000 to $12,000 more than comparable gas-powered ones, although available tax credits can close much of the gap. 

For instance, the federal government gives consumers up to $7,500 tax credits for electric-car purchases, while California kicks in another $2,500 in state tax credits for buyers who live there. "You can get pretty close on prices depending on the state you live in," O'Dell says.

Read on to check out the five models at the top of this year's rankings, or click here to see how more than 1,000 vehicles in the 2000-15 model years rate for total lifetime pollution.

The "Green Scores" listed below rate each vehicle's projected pollution output over a 120,000-mile lifespan on a scale of zero to 100, with the average 2015 model scoring 37.

Fuel-efficiency levels listed for electric cars refer to "miles per gallon equivalent," or "mpge." That's the U.S. Environmental Protection Agency's estimate of how far a vehicle's rechargeable batteries can take you using the amount of electricity equal to a gallon of gasoline's energy content.

Dollar figures below reflect manufacturer's suggested retail prices for each model's base 2015 version, excluding destination fees, rebates and tax credits (unless otherwise noted).

Fifth-greenest 2015 model: Nissan Leaf
Green Score:
56.5 (out of a possible 100)

The Leaf, which in 2011 became the first mainstream electric car sold in America, offers drivers an amazing 126 mpge in city driving and 101 mpge on the highway. 

The EPA also estimates that the 107-horsepower vehicle can travel 84 miles between recharges, which experts say is more than enough for many commuters.

O'Dell, who drove a Leaf for three years, says he found the small four-door hatchback "comfortable and fairly roomy" even though he's 6-foot-2." You can also fully recharge your Leaf in just four hours using a 240-volt outlet, which costs around $600 to install in your home.

Lastly, Leafs start at a fairly modest $29,010, or $21,510 after factoring in the available $7,500 federal tax credit. As noted above, California and some other states also kick in as much as $2,500 in additional tax breaks, while you can often lease a Leaf for $199 a month or less.

Fourth-greenest 2015 model: Toyota Prius c
Green Score: 56.9

The Prius c hybrid is the only non-electric vehicle to make the council's top-five green list.

Vaidyanathan says that's partly due to the subcompact's incredible fuel efficiency (53 mpg/city and 46 mph/highway), but also attributable to its light weight — about 2,500 pounds. That reduces the pollution involved in hybrid's construction and eventual disposal.

Edmunds expert O'Dell adds that the $19,540 car, the smallest model in Toyota's Prius lineup, offers green-car buyers access to the Japanese automaker's famous reliability and build quality.

But he adds that the Prius c's size "isn't going to fit the needs of everyone," and its small 99-horsepower gas/electric power plant "probably isn't something that you'd use to rip through the mountains."

Third-greenest 2015 model: Fiat 500e Electric
Green Score: 58.6

This electric version of the well-regarded Fiat 500 subcompact gets high marks for sporty handling, outstanding fuel efficiency, a modest price and easy parking, although it's for sale only in California and Oregon as of now.

O'Dell says the 500e's 111-horsepower electric motor offers rocket-fast acceleration, making the car "a real kick to drive." The editor also calls the Fiat's interior "comfortable and roomy," while the EPA rates the model's fuel efficiency at 122 mpge/city and 108 mpge/highway and puts its range between charges at 87 miles.

Add in the fact that prices start at a fairly modest $31,800 ($24,300 after deducting the federal tax credit) and O'Dell sees the 500e as good choice for "green" drivers. Fiat also currently offers a $139-a-month lease on the car.

Second-greenest 2015 model: Chevrolet Spark EV Electric 
Green Score: 59.2

The Spark EV is one of only three 2015 electric cars you can buy for less than $20,000 after factoring in the $7,500 federal tax credit.

A base version will cost you just $26,670, or $19,170 after taking the tax break into account. The trails just the Mitsubishi i-MiEV and Smart Fortwo Electric as the lowest-priced electric car sold in America.

You can also lease a Spark EV for just $176 a month — although, again, the model is available only in California and Oregon right now.

The EPA rates the Spark EV at 128 mpge/city and 109 mpge/highway and estimates the car can go 82 miles between charges.

On the downside, the model takes a relatively long seven hours or so to fully recharge at 240 volts, as well as some 20 hours to juice up using a standard 110-volt household outlet. 

O'Dell adds that while the 140-horsepower Spark EV is "very peppy, it's small and relatively bare-bones. It's a great choice for an all-electric 'commuter' car, but it's not something that I'd recommend as a 'principal' car." 

Greenest 2015 model: Smart Fortwo Electric
Green Score:
61.1

The tiny Smart Fortwo Electric takes first place in the council's study thanks to a combination of great fuel efficiency and the smallest dimensions of any 2015 car — electric, hybrid or gas-powered — sold in America.

The two-door's 47-horsepower electric motor gets an estimated 122 mpge/city and 93 mpge/highway, while Vaidyanathan says the car's small size (it's less than 9 feet long) means its construction creates relatively little pollution.

O'Dell says the model's dimensions also make for easy driving and parking in crowded urban areas. "If you live in New York City and do all of your moving around in Manhattan, then a Smart Fortwo Electric makes a lot of sense," he says.

The car also starts at a relatively low $25,000, or $17,500 after deducting the federal credit.

That said, the Fortwo Electric only has an estimated 68-mile range between charges and takes a fairly long six hours to juice up at 240 volts. O'Dell adds that the car has "a very firm ride that can be uncomfortable if you live in a city with rotten roads."

— Written by Jerry Kronenberg for MainStreet