The government has formalized its mandate that the average fuel economy of the new-car fleet by 2025 must be 54.5 miles per gallon.

That means that through a complicated system of government arithmetic, cars we buy by 2025 are going to have to be a whole lot more fuel efficient than they are today.

What's that mean for you the consumer? Very few, if any, V8 engines, except on trucks and SUVs that really have to work to pull loads. It also means more hybrid vehicles, and more families opting for an electric car, or extended range electric vehicle like the Chevy Volt and new Ford C-Max, as a second or perhaps primary vehicle.

While the push for much greater fuel economy can be controversial (i.e. Nobody is taking away my Chevy Suburban!) there are more and more vehicles coming from automakers for us to choose from. And it starts this Fall.

We thought we would give you a preview of some of the more interesting new hybrid and EV choices from some of the biggest and best loved automakers arriving over the next few months.

Tesla is the company that believes there is a strong business model for electric luxury cars. According to the EPA, the Tesla Model S gets a miles per gallon equivalent (MPGe) of 89 (combined), 88 (city) and 90 (highway). Green Car Reports says the range has been declared to be 265 miles, which beats the previous distance champion – the Tesla Roadster – by 20 miles.

To compare, other pure electric cars on the market include the Honda Fit at 118 combined MPGe, the Mitsubishi i with 112 MPGe, the Ford Focus Electric with 105 MPGe and the Nissan Leaf with "just" 99 MPGe.

Even at the bottom of this particular list, these are impressive numbers for the Model S. Still, that range figure only applies to the top-of-the-line version with the 85-kWh battery that starts at $69,900 (or an eye-popping $97,900 in so-called Signature Performance guise).

If you are into parting with those kinds of dollars for an EV, all those numbers will make sense to you.

This Fall, Chevy is selling a new mini-car, called Spark, that is meant to compete against the growing number of mini cars like the Fiat 500, Scion iQ, Mazda2 and so on.

The five-door Spark will test America's appetites for small car life with a starting price of just $12,995 (including delivery) when it arrives in Chevrolet showrooms. Available in a trio of trims, the lineup will start with the well-equipped LS model that includes a whopping 10 airbags, air conditioning, power windows, OnStar and 15-inch alloys.

And we will also have an option of a Spark Electric. Hey, that sounds petty cool and is as name-appropriate as the Volt. The Spark EV hits dealerships sometime in the first half of 2013. We'll know pricing then, but we hear the range on a single charge should be about 80-90 miles.

BMW is in the same boat as every other automaker and must produce more hybrids, EVs and the like to meet stiffer fuel economy standards. Enter the i3, an electric car that the company expects to be selling through dealerships by 2013, but we are including in our gallery now because, well, it is cool, and we have a lot of anticipation building up.

BMW has started testing its electric-drive i3 in Northern Europe. As the German automaker looks to gather more testing information on the model it may launch as early as next year, according to Green Car Reports.

The battery-electric i3 is expected to have a single-charge range of about 80 miles and a 0-60 mile-per-hour acceleration time of about 8 seconds.

The ILX is built off the same platform as Honda's venerable Civic, but the styling is distinct enough that you won't be totally embarrassed for paying Acura prices for a Civic.

The Hybrid ILX has a 1.5-liter engine and continuously variable gearbox that is shared with the Civic. With 91 horsepower from the engine and a maximum of 23 more horses from the electric motor, the ILX Hybrid is predictably passive in its pace. Slapping the shifter into Sport mode helps a little, but there's just no way the combined torque of 127 lb-ft from 1,000 to 3,000 RPM will get the vehicle moving in a hurry. It's not horrible when meandering away in urban settings, but that's the most praise we can offer its ability to get the show on the road.

The ILX Hybrid is rated at 39 mpg in the city and 38 on the highway. That's not exactly bad, but it's uncompetitive with the 43/40 rating of the Lexus CT200h. If you plan to do most of your driving on highway, the Audi A3, when equipped with its optional turbo diesel engine, manages 42 mpg on the highway. Both of those models are in the same ballpark as the ILX Hybrid's $28,900 (*add $895 to all prices quoted for destination) starting price, which jumps to $34,400 when optioned with the Technology package.

It might only be available to lease in limited numbers in only a few areas, but the Honda Fit EV certainly has one thing that's tremendously good about it: an official EPA rating of 118 MPGe and a range of 82 miles. Specifically, the all-electric Fit gets 132/105/118 city/highway/combined MPGe. Honda says the little EV is the most efficient vehicle the EPA has ever tested, but we're not sure about that.

Leases began "in select California and Oregon markets this summer, and now the car is headed to East coast rollout in early 2013." The Fit EV leases for $399 a month and has an MSRP of $36,625. The supply is lintier, so if you want one, get thee to a dealer that has one.

Ford is introducing a slew of new advance-powertrain models over the next year. These include full hybrid, plug-in hybrid and all-electric vehicles. One of the first to arrive is the all-new C-Max Hybrid, which has the Prius, specifically the Prius V, aligned in its crosshairs.

Thanks to its high roofline (63.9 inches), the Ford boasts 52.6 cubic feet of space behind the first row and 24.5 cubic feet behind the second row. It also offers more headroom in both the front and rear seats than the Prius V (41.0 and 39.4 inches, versus 39.6 and 38.6 inches), according to Ford. Add it all up, and the C-Max Hybrid offers 99.7 cubic feet of passenger space (the Prius V offers slightly less at 97.0 cubic feet). The C-Max's standard five-place cabin also features a 60/40 split-fold-flat second row, designed with one-handed operation in mind, for additional utility.

Under the front hood of the 2013 Ford C-Max Hybrid is a naturally aspirated 2.0-liter Atkinson cycle gasoline-fed inline four-cylinder rated at 141 horsepower that has been mated to a 35-kW permanent magnet AC synchronous electric motor for a combined system power of 188 horsepower.

The C-Max Hybrid earns 47 miles per gallon in the city and 47 mpg highway (47 combined), while the Prius V earns 44 mpg city and 40 mpg highway (42 combined). Thanks to its 13.5-gallon fuel tank, the C-Max will deliver a 570-mile cruising range

The C-Max Energi is an extended range electric car similar to the Chevy Volt and Toyota Prius Hybrid. How does it work? In the case of the Energi, it means you can drive on a battery charge for about 20 miles. Then, the gas-fed motor kicks on and continues to power the car through the battery. You won;t run out of power unless you run out of gas.

The engine in the Energi, like the Volt, does not re-charge the battery. You have to plug in somewhere for that. The idea is to charge the car up overnight at your house while electricity is cheapest. This kind of car is ideal for someone who puts less than 35 miles a day on their car, or as a commuter if there is a charger at the workplace garage--which is becoming more commonplace.

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