Comparing hybrid sedans is a little like pitting Rush Limbaugh against Al Gore in a Thunderdome-style death match. The fight itself might put you to sleep, but the results, which speak volumes about the commitment of the combatants, will have everyone taking notice.

Despite the politics, now is a good time to compare hybrids. Environmental factors, ever-increasing fuel costs and the simple need for social responsibility are creating a market ripe for the hybrid. Manufacturers are responding with midsize sedans — the most popular car segment in the largest car market in the world.

We've assembled the three big players in this segment: Nissan's 2007 Altima Hybrid, Saturn's 2007 Aura Green Line and Toyota's 2007 Camry Hybrid. We left out Honda's Accord Hybrid since it's been discontinued for the 2008 model year. We're simply looking for the best car by factoring in fuel economy, performance, price and usability in an all-out slugfest of green.

Who's Who?
Toyota is a dominant player in the American hybrid market with its Prius, now in its second generation, which has set the standard for efficient operation and distinctly dorky styling. But it's the Camry that has been the best-selling car in the U.S. for eight of the last nine years, so producing a hybrid version that incorporates the efficiency of the Prius with mainstream usability and styling only makes sense.

Just like the standard Camry, the hybrid version comes loaded with features like dual-zone climate control and Toyota's Smart Key system with push-button start. Our test car also has plenty of options, including the $1,300 Leather Package and $1,200 voice-activated DVD-based navigation and audio system (with satellite radio). The $940 Moonroof Package, $470 Comfort and Convenience Package and $277 Preferred Accessory Package brought the total to $30,667, including the $580 destination fee.

At $30,535 as tested, Nissan's Altima Hybrid undercuts the Camry by only $132. Its $5,250 Connection Package with XM includes heated leather seats, a power-sliding moonroof, Bluetooth capability, a Bose six-disc CD changer with XM Satellite Radio and nine speakers, and many other amenities. The Altima also includes $270 in floor mats and aluminum sill plates.

Saturn's Aura is far less expensive at only $23,070. It has only one option — the $375 Preferred Package, which adds eight-way power adjustment to the driver seat, steering-wheel-mounted audio controls and heated power-adjustable outside mirrors.

All three cars come standard with four-wheel antilock disc brakes, head curtain and side airbags, traction control and stability control. Regenerative braking, which turns kinetic energy from braking into electrical energy to charge the hybrid system's batteries, is a key feature in most hybrids and all three cars utilize it. Sixteen-inch alloy wheels are also standard for all three cars.

The Routine
Testing three hybrid sedans might not produce the same thrill as our last 500-horsepower coupe shoot-out, but there is something refreshing about exceeding 40 miles per gallon during your homeward commute. Some editors even thought of the Camry's fuel economy display as a personal challenge to their driving skill.

For two weeks we drove all three cars in every environment they would ordinarily see as family sedans. We loaded them with people and cargo, observed their strengths and shortcomings and took them to the test track to measure their performance. We bickered about the couchlike ride quality of the Camry and were in awe of the directness of the Altima's steering. And we all liked the reasonable price of the Aura.

We skewed our scoring criteria to focus on the priorities of the hybrid buyer. Fuel economy contributed a major amount to each car's overall score, while performance was scaled back accordingly. Feature content and our 28-point evaluation that covers everything from powertrain performance to cupholders have been weighted 15 and 20 percent, respectively. As-tested price, the most heavily weighted category, accounts for 30 percent of each car's total score.

All Hybrids Are Not Created Equal
Understanding the differences between the two types of hybrids tested here is critical to both making an informed purchase decision and reconciling the differences in each car's performance and efficiency. Both the Camry and Altima use Toyota's Hybrid Synergy Drive. (Although Nissan doesn't use the Synergy Drive nomenclature, it has licensed the technology as a stopgap until its own system is ready by 2010.)

The Camry Hybrid comes standard with a 2.4-liter four-cylinder engine rated at 147 hp and 138 pound-feet of torque that augments its 30-kilowatt electric motor. Nickel metal-hydride (NiMH) batteries are capable of delivering 30 kilowatts of power. Drive is sent through a unique continuously variable transmission (CVT) that utilizes two planetary gearsets instead of the bands and clutches typical of most CVTs. The same components are used in the Altima, where they're coupled to a 2.5-liter four-cylinder engine rated at 158 hp and 162 lb-ft of torque. Nissan also calibrates the system to suit the Altima's sporting identity — a difference we could actually feel.

Toyota's design is elegant and effective for several reasons. First, it allows the car to be propelled entirely on electric power under many conditions and many speeds, and this saves fuel. Its unique CVT allows power to come from either the gas engine or electric motor, providing the ability to blend power sources for optimal efficiency.

GM's hybrid system combines the base Aura's 2.4-liter four-cylinder power plant with an electric motor-generator. This generator produces 4 kilowatts of power, enough to spin the crankshaft pulley via a heavy-duty Kevlar ribbed belt. The Aura's NiMH battery pack produces 10 kilowatts of power.

The Aura's electric motor is used to start the gasoline engine and can add small amounts of power under high-load conditions. Both the electric motor and gasoline engine, which are coupled in a fixed ratio, drive a conventional four-speed automatic transmission. Like the Camry and Altima, the gasoline engine shuts off under certain conditions and the electric motor restarts it. But with far less electric power than the Toyota and Nissan, the Saturn offers full electric propulsion only up to about 3 mph. Consequently, the gasoline engine is forced to do most of the work.

The Camry and Altima are each certified as Advanced Technology-Partial Zero Emissions Vehicles (AT-PZEV). This means the tailpipe emissions are 90 percent cleaner than the average new vehicle, the fuel system has zero evaporative emissions and the powertrain carries a 15-year/150,000-mile warranty. Meanwhile, the Aura is certified as a Low Emissions Vehicle (LEV).

I Want My MPG
We measured fuel economy using two sets of criteria. First, we performed a test in which all three cars were driven over two road loops — one highway (120 miles) and one city (50 miles). Driving in a group and using the same driving style and similar speeds ensured a controlled environment for all three cars. One driver refueled all three cars at the same pump using the same fill technique on both loops.

All accessories (air-conditioning, radio, etc.) were set identically during these tests to control as many variables as possible. Both the Camry's "ECO" button and the Aura's "Hybrid A/C" button, which limit the ventilation system's energy consumption, were engaged. The combined fuel economy numbers produced during these tests were used in our fuel economy scoring, which contributes to 15 percent of each car's overall score.

Toyota proved it's got the fuel economy game wrapped up, as the Camry produced the best combined mileage of our test group with 43.2 mpg over both loops — 44.5 mpg in the city and 42.6 mpg on the highway. The Altima's fuel economy in the city actually proved marginally better than the Camry's at 47.3 mpg, but its 38.1 mpg on the highway dropped its combined rating to 40.1 mpg.

The Aura wasn't even close. Its combined fuel economy was just 26 mpg, largely as a result of its 18.9 mpg in city driving — where it doesn't benefit from true electric-only propulsion like the Camry and Altima. On the highway loop, the Aura produced 31.5 mpg.

Second, we calculated observed fuel economy over our entire time with each car, just as we do with all of our road test vehicles. Though this data isn't gathered in identical controlled conditions, it provides a useful idea of the fuel economy each car is likely to produce in the hands of the average drivers during everyday driving. The Camry again came out on top, producing 32.6 mpg. At 31.5 mpg, the Altima is a close 2nd, while the Aura lags behind at 24.5 mpg.

3rd Place: 2007 Saturn Aura Green Line Hybrid
The Aura is a big step forward for GM when it comes to the midsize sedan segment. Its Epsilon platform is a capable player dynamically and its interior is a huge leap ahead of previous efforts. Problem is, the target keeps moving. GM's Japanese competition always seems to stay one step ahead when it comes to design and quality.

The factor that hurts it worst in this test, however, is that its fuel economy simply doesn't compete with other hybrid sedans. Equipped with a mild-hybrid powertrain that lacks true electric-only propulsion, the Aura burdens its gasoline engine more than its full-hybrid competition. Even though our scoring system emphasizes the importance of price more than any other factor, the Aura's $7,500 price advantage over the 2nd-place Altima isn't enough to overcome its deficit in fuel-efficiency.

We'll admit that it would take more than 18 years to recoup the price difference between the Altima and Aura in fuel-cost savings alone. (We're using the current average U.S. fuel cost, a rate of 15,000 miles per annum and the same observed fuel economy we achieved — 31.5 and 24.5 mpg, respectively.) But this is an economic argument, not an environmental one, and the Aura still consumes 136 more gallons of fuel annually than the Altima.

The Aura's acceleration and handling didn't win it any points against its competition, either. It was off the pace in acceleration to 60 mph, where it registered an embarrassing 11.0-second time — more than 2.5 seconds behind the 2nd-place Camry. The story is the same in the quarter-mile, where the Aura posts a 17.9-second time at 81.8 mph.

Handling and braking numbers brought the Aura closer to its competition. It stops from 60 mph in 139 feet — 3 feet longer than the Altima and 5 feet longer than the Camry. Its 0.74g skid-pad performance is on par for the class and its 58.7-mph slalom speed is only a few clicks slower than the 2nd-place Camry.

The Aura did win points with several features that the Altima and Camry simply don't have. Its mild hybrid system requires fewer batteries, which are traditionally packaged in the trunk of most hybrid sedans. Less intrusion by the batteries means more trunk space than both of the other cars. The Aura also has a 60/40-split folding rear seat, which the Altima didn't have, while the Camry makes a half-hearted attempt with a split-folding design that's partially blocked by batteries. The Aura is also the only car in the group that comes standard with an emergency assistance system (OnStar).

The Aura is a tough sell when compared to the competition. Its primary benefit is the ability to shut down the gasoline engine when stopped, but without the ability to mix power sources it can't compete with the Camry and Altima's fuel economy. Its interior and exterior styling and quality improvement are welcome changes, but the gap to the class leaders still isn't closed.

2nd Place: 2007 Nissan Altima Hybrid
The Altima's logbook notes are clear: "Finally. A hybrid with decent steering and a responsive chassis. What took so long?"

What took so long is a misconception by car manufacturers that a hybrid powertrain needs to have unique (i.e., repugnant) styling, and that bizarre dynamics are acceptable. Nissan has proven otherwise with the Altima Hybrid, which takes 2nd in this test by a mere 2.3 points. The Altima is easily the quickest car of this bunch and it's also the personal choice for every editor who participated in this test.

So why didn't it win? Because the Camry gives you more features for the same money and produces marginally better fuel economy. Both the Altima and the Camry are available with navigation, but our Camry test car delivers the goods for only $132 more than the non-nav-equipped Altima. The Altima's batteries also consume significant cargo room in the trunk, reducing its volume to 9.1 cubic feet compared to the Camry's 10.6 cubic feet.

At the track the Altima produces impressive acceleration, proving that hybrid powertrains can increase performance as well as efficiency. Its best-in-test 0-60-mph sprint of 7.6 seconds and quarter-mile performance of 15.6 seconds at 91.5 mph were considerably quicker than the 2nd-place Camry.

Handling tests didn't produce the same margin of victory for the Nissan, since the Altima is saddled with long-wearing tires similar to those of the other contenders. But with more immediate steering response and a more heavily damped ride, the Altima is far more responsive during cornering than the others.

Around the skid pad, the Altima ties the Camry at 0.76g but is slightly quicker through the slalom (61.4 mph vs. 61.0 mph). It takes 2 feet more to stop the Altima from 60 mph than it does to stop the Camry (136 feet. vs. 134).

One of the Altima Hybrid's drawbacks is simply its availability. Nissan has opted to sell it only in the eight states that follow California's stringent emissions standards: California, Connecticut, Maine, Massachusetts, New Jersey, New York, Rhode Island and Vermont.

1st Place: 2007 Toyota Camry Hybrid
It's the Camry's abundant features, comfortable ride and fuel-sipping efficiency that take it to the top of the podium in this test. Just like the standard Camry, the simple fact is the Camry Hybrid gives you a lot of car for your money.

Part of the value comes in the form of real-world performance. The Camry hits 60 mph in 8.4 seconds and stops the quarter-mile clock in 16.2 seconds at 87.5 mph. Sixty to zero required 134 feet — the shortest stop in this group. And despite a softer ride, the Camry nearly equals the Altima's handling numbers by circling the skid pad at 0.76g and splitting the slalom cones at 61.0 mph.

The Camry Hybrid is also refined and easy to drive in every way a midsize sedan should be. There's ample driver and passenger space and plenty of adjustability in everything from the seats to the pollen-filtered climate control. The Camry isn't the most fun-to-drive car here, but its value and utility prove once again that Toyota understands the midsize sedan segment better than any other company.

Details like an Atkinson-cycle gasoline engine (a distinction that helps the Camry nip the Altima in fuel economy) and packaging designed to accommodate the hybrid batteries with minimal intrusion into the interior speak volumes for Toyota's commitment to hybrids. And in a game where commitment translates directly into real-world benefits like preserving natural resources and reducing emissions, we'll give it the win every time. Even Rush couldn't argue with that.