Yep, it's almost the end of the year, which means reams of roundup stories from all your favorite auto websites.

Nope, we're not that different: We've got one too. Here's our take on the five most important stories--or perhaps themes--of 2011 in the growing world of green cars.

New fuel economy rules: 54.5 mpg CAFE by 2025

The biggest story of the year is the new gas-mileage requirements jointly issued by the NHTSA and EPA--under the encouragement of the Obama White House, and with signoff from most if not all of the major automakers. (Auto dealers are still fighting the rules.)

The new corporate average fuel economy (CAFE) rules cover model years 2017 through 2025, and include rises of 3 percent per year for trucks and 5 percent for cars.

The result is that by 2025, the average vehicle will achieve 54.5 miles per gallon on its CAFE tests--which translates to the low to mid 40s on a new-car window sticker (due to outdated CAFE test cycles).

EPA gas-mileage label (window sticker), design used starting in model year 2013

EPA gas-mileage label (window sticker), design used starting in model year 2013

How will we get there? Sure, there'll be more hybrids and some plug-in cars. But the vast majority of the increased gas mileage will come from smaller, more efficient engines.

We're already seeing this, with four-cylinder engines becoming the de facto standard--neither the Hyundai Sonata mid-size sedan nor the 2013 Ford Escape compact crossover will offer a V-6--and V-8s being relegated to trucks and low-production sports cars like the Camaro and Mustang.

Even pickup trucks now come increasingly with V-6 engines. Just four months after Ford offered a 3.5-liter Ecoboost direct-injected and turbocharged V-6 in its F-Series pickups, that engine was racking up one-third of all F-Series sales.

A year after its launch, more Ford F-Series trucks are now sold with V-6s than with V-8s--which hasn't happened since 1985. As of yesterday, Ford said it had sold more than 100,000 EcoBoost direct-injected and turbocharged V-6 engines in F-Series pickups during 2011.

2011 Ford F-150 EcoBoost rear view - Drive Tour 2011

2011 Ford F-150 EcoBoost rear view - Drive Tour 2011

Surprise, surprise: Good small cars actually sell

Since the 1970s, it had been an article of faith in Detroit that "small cars" had to be cheap "econoboxes" without too many features--because real American car buyers wanted mid-size or full-size sedans, crossovers, and pickup trucks.

Only weird coastal buyers and the truly poor actually wanted or, even worse, needed small cars.

Which is how Volkswagen in the Sixties, then Toyota, Honda, and Nissan in the Seventies and Eighties, and Hyundai in the Nineties, collectively thrashed GM, Ford, and Chrysler, and essentially swallowed the entire market for compact and subcompact cars.

It's taken 40 years, but now--finally--domestic makers offer truly competitive compacts (Ford Focus, Chevy Cruze) and subcompacts (Ford Fiesta, 2012 Chevrolet Sonic). And, guess what? They're selling, and selling well.

2011 Chevrolet Cruze Eco, New York City, March 2011

2011 Chevrolet Cruze Eco, New York City, March 2011

The Chevy Cruze compact, in fact, is the best-selling sedan GM makes. Its sales figures are roughly three times that of its unloved Chevy Cobalt predecessor. Why? Because it's stylish inside, handsome on the exterior, comfortable and very quiet to ride in gets decent gas mileage--and can be ordered with lots of luxury features.

Ditto the compact Ford Focus. And the same applies to the subcompact Ford Fiesta and Chevy Sonic, and may prove to be the case for the crucially important new 2013 Dodge Dart compact that will replace the aged and uncompetitive Dodge Caliber.

So forget 350 V-8s; the new magic numbers are 40 mpg highway from 1.4 liters of engine in those new compacts.

There's been some bracket creep, mind you. The "subcompact" Chevy Sonic is the size of a "compact" Honda Civic from 15 years ago. That reflects the space devoted to vastly superior crash-safety design, and the weight of all those new features, power accessories, in-dash displays, and so forth. This ain't your father's subcompact.

Ford Focus ST, launched at the 2011 Los Angeles Auto Show

Ford Focus ST, launched at the 2011 Los Angeles Auto Show

But even minicars, represented for an entire decade solely by the Mini Cooper, are landing in the U.S. The 2012 Fiat 500 gets positive reviews, the Scion iQ is about to arrive, and next year even all-American Chevrolet will import its 2013 Spark minicar.

They wouldn't do it, folks, if they didn't think they could sell some.

Real electric cars from major automakers go on sale--for real

The bulk of U.S. car buyers are only dimly aware, if at all, that you can now buy electric cars that plug into the electric grid to recharge the battery packs that power them.

But early adopters and the environmentally aware have snapped up the limited supplies of Nissan Leaf and Chevrolet Volt plug-ins, supplemented by two new end-of-year-entries: the Fisker Karma and Mitsubishi 'i'.

All in all, roughly 17,000 cars with plugs will have been sold once 2011 sales wrap up 10 days hence. That's about triple the number sold over several years of California's first attempt to require zero-emission vehicles, in the late 1990s and early part of this decade.

And it's an indication that, finally, global automakers are taking plug-in cars seriously.

2012 Mitsubishi i - First Drive, U.S.-spec MiEV

2012 Mitsubishi i - First Drive, U.S.-spec MiEV

It's due to both the maturation of lithium-ion cell technology and the prospect of further regulations in Europe, Asia, and North America that require lower emissions and higher fuel efficiency.

It'll be a slow, slow rollout. Even by 2020, most analysts think that only about 1 percent of total production--which is to say, perhaps 1 million of the 100 million vehicles the global industry will make--will have plugs. Up to 25 percent may have some form of hybrid system.

But, this time it's real. And barring the prospect of radical rollbacks in regulations across the globe--combined with $2-per-gallon gasoline into eternity--this time we're not going back.

Startup automakers face tough, tough sledding

Around here, we get asked about Tesla's chances a lot. We usually respond by pointing out that the last automaker founded in the U.S. from scratch by entrepreneurs that's still with us today is Chrysler ... and that happened in 1924.

In other words, starting a carmaker is really, really, really hard. And expensive. And time-consuming.

Aptera 2e development prototype at company offices in Vista, California

Aptera 2e development prototype at company offices in Vista, California

The ongoing shakeout in startup automakers just proves the point. Earlier this month, Aptera closed its doors, dashing the hopes of the 5,000 potential buyers who'd put down money to reserve one of their ultra-aerodynamic, three-wheeled, all-electric, plastic-bodied two-seat motorcycle-cars.

Over the last three years, under CEO Paul Wilbur, the company bet its fate on receiving low-interest Department of Energy loans. That didn't pan out too well.

Other startup makers hoping for government subsidies are in similarly precarious positions.

NextAuto (nee V-Vehicle Co.), which wanted to build a low-cost plastic-bodied economy car, has been turned down twice by the DoE.

Carbon Motors, which hopes to build a carbon-fiber bodied E7 police cruiser that will use BMW turbodiesel engines, hasn't heard back on its loan application.

And Bright Automotive, which hopes to build a 100-mpg plug-in hybrid urban delivery van, is waiting on the DoE as well. At least GM owns a portion of Bright, perhaps giving it a slightly ... errrr ... brighter future.

2012 Fisker Karma EcoSport

2012 Fisker Karma EcoSport

In the end, perhaps the only startups to win DoE loan guarantees will be Fisker Automotive (now delivering its first 2012 Karma extended-range electric luxury sport sedans) and Tesla Motors [NSDQ:TSLA].

Even there, industry observers expect both companies to be bought by global carmakers if they survive into mass production. As we opined earlier this year, CEO Elon Musk says Tesla won't be sold, but analysts suggest he is wrong.

After all, if a long-established maker of sport sedans that pioneered numerous technologies and is known globally--with a rabid if small fan base--can't survive with all its brand recognition, what's the future for unknown startups?

RIP Saab.

Right wing targets Chevy Volt, Nissan Leaf sails through unscathed

By now, General Motors is well aware that some portion of the electorate and the political spectrum really, really hates the company.

And they especially hate the Chevy Volt, the extended-range electric car that GM desperately wants to act as a technology halo car--just as the Prius hybrid has done, so successfully, for Toyota.

2011 Chevrolet Volt destroyed in Barkhamsted, CT, garage fire; image from WTNH News 8 report

2011 Chevrolet Volt destroyed in Barkhamsted, CT, garage fire; image from WTNH News 8 report

Alarmist headlines about two garage fires in which Volts were destroyed kicked off the Volt-bashing. Both cars were subsequently exonerated, but the "Volt sets garage on fire" headlines had already gone out, courtesy of Matt Drudge and others.

Then a battery pack in a Volt wrecked during an NHTSA crash test caught fire--three weeks after the test. GM acknowledged it hadn't propagated instructions on how to drain the battery pack after a major crash, just as emergency responders would drain a gas tank.

One commenter quipped at the news, "So I should make sure to get out of my wrecked Volt within three weeks?"

But the incident didn't come to light for several months. Then a second pack, being studied in a lab in an attempt to replicate the condition, did indeed catch fire.

Cue the "Volt fires" articles, along with hysterical accusations of massive coverups. As usual, Obama was probably at fault.

Around the same time, GM admitted that Volt sales wouldn't reach the first-year goal of 10,000. Chevy says it's a result of its commitment to put the car on sale across thousands of dealers in all 50 states by the end of this year.

Cue more headlines on "Volt sales disaster" and so forth. None of them, perhaps predictably, bother to note the context that GM shut down the Detroit-Hamtramck plant that builds the Volt for more than a month to retool it. As we keep saying, today the problem isn't demand for Volts--California dealers have waiting lists. It's supply and distribution.

2011 Nissan Leaf SL

2011 Nissan Leaf SL

Meanwhile, the Nissan Leaf battery-electric car has sailed through unscathed. It's had no reported battery-pack fires (its pack is not liquid-cooled, unlike the Volt's, which possibly lowers the chance of short circuits after major accidents).

Its sales have averaged just about 1,000 vehicles per month--though it will be nowhere near meeting the sales goal of 20,000 it had put forth a couple of years ago.

In fact, Nissan might seem more vulnerable, since it accepted $1.4 billion in low-interest loans from the Department of Energy advanced technology vehicle manufacturing program. That's the same DoE being pilloried for losing several hundred million dollars on loans to failed solar-panel maker Solyndra.

The money will go toward building a lithium-ion cell manufacturing plant in Smyrna, Tennessee, next to the assembly plant where the Leaf will be built alongside Altimas and other Nissan gasoline models.

Nissan got the second-highest loan amount of any carmaker; Ford was first at $5.9 billion, the bulk of that cash going toward speeding production and launch of its EcoBoost line of smaller, more efficient engines across all its vehicle lines.

Yet nary a peep out of the anti-Volt forces about The Gummint subsidizing sales of the Nissan Leaf electric car. Wonder why ....

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