Winning a Nobel Prize comes with a number of perks.

First, there’s a $1.5 million grant…which you are morally obligated to spend on further research in your field, or give to a good cause, rather than blowing it on a couple of cases of akvavit liquor and smoked salmon from the duty free shop on your way back from the award ceremony in Scandinavia.

Not a problem, because when you get home you can sit back, relax and bask in the international fame that comes with being a Nobel laureate…and lasts about as long as it takes for the recycling truck to pick up the newspapers.

Sad, but true.

Go ahead, name two Nobel Prize winners from the past five years. Unless your job description includes the terms "mechanism design theory" or "eukaryotic transcription," I’ll wager that you can come up with one.

Al Gore.

He won the 2007 Nobel Peace Prize for encouraging us to stop doing things like driving around in carbon dioxide-emitting automobiles, which brings up an interesting point the Nobel committee didn’t ask.

What does Mr. "Green," himself, drive?

Even without the cash prize, Environment-Al is a pretty well-off guy. His net worth these days is estimated to be over $100 million, which means he probably can buy just about any vehicle that he cares to. So it’s no surprise that he chooses to drive only the very best.

A Mercury Mariner Hybrid.

Click here for video.

Laugh all you want, Rolls-Royce owners, but the Mariner Hybrid, along with its corporate twin, the Ford Escape Hybrid, is the highest-mileage SUV you can buy in the United States, making it the best in that dubious, but increasingly important, category.

For the former vice president, driving a Mariner Hybrid is a win-win-win situation. Good gas mileage, more room and comfort than the economy car-sized alternatives and, most important for a once and future politician, it’s American.

With an EPA combined rating of 32 miles per gallon, the Mariner Hybrid gets 4 more miles per gallon than the next-best Saturn Vue Green Line at 28 mpg, and 6 more than the Toyota Highlander’s 26 mpg.

•Click here for photos.

More impressive is that the Mariner Hybrid’s fuel economy is 45 percent better than the conventional four-cylinder Mariner, which returns a paltry 22 mpg in the same test. The Mariner Hybrid costs over $5,000 more to buy, and you’re not likely to make that up in gas savings during the time that you own it, but federal and state hybrid tax incentives may be available to you that can narrow that price gap.

Besides, you’re not buying it for yourself, right? You’re buying it for the planet.

These figures are for the front-wheel drive model, like our test vehicle, but you also can order a four-wheel-drive version that gets 28 mpg — best in that category, as well.

Starting at $25,765, the Mariner is a slightly dressier, less rugged-looking version of the Ford Escape. Other than a couple of "Hybrid" logos on the exterior, and a few quirks in the way it goes about its business, the Mariner Hybrid looks and rides nearly the same as the standard version.

Despite having ground clearance almost as high as a Jeep Wrangler’s, it has a stable ride on the pavement, where most Mariners spend their days, with the composed feel of a car rather than the bounce and jounce of a truck.

It’s not luxury sedan-smooth, but there is an unexpected absence of body roll for a vehicle that stands this tall, even on the twisty mountain roads of New Jersey’s ski country where I spent a day with the Mariner (no, I’m not making this up; there is such a place).

Driving along in full-electric mode, which technically you can stay in for short distances at speeds under 25 miles per hour on a charged battery, the Mariner gets from traffic light to traffic light just fine. Only the soft whine of the electric motor reminds you that it’s not just coasting down a hill.

Conditions need to be perfect to maintain that 25-mph speed for any length of time, but crawling along in bumper-to-bumper traffic, the engine rarely lights up, and I regularly putt-putted around at 15 mph without dipping into the gas tank. When it does start, the engine comes on with just a light shudder that barely gets noticed after a few hours behind the wheel.

What does take some effort to get used to is the way the 2.3-liter four-cylinder delivers its power to the wheels. Rather than a standard automatic transmission, the Mariner is equipped with a continuously variable transmission, also known as a CVT.

Generally speaking, CVTs have a design similar to what you find on a bicycle, but in place of the two sets of gears connected by a chain, there are two cone-shaped pulleys connected by a belt. This allows the belt to seamlessly move through an infinite number of gear ratios so that the engine can operate at its most efficient speed more often, rather than revving up and down as it shifts through a limited number of gears.

If you’ve ridden your bike lately, like a good hybrid-shopper should, you can appreciate how much easier and more effective this method is than having to build up leg speed every time you shift gears.

Of course it's not as simple as that, and CVTs come in a variety of designs. In fact, the one in the Mariner actually uses a complex set of gears to achieve its gearless feel, but the basic concept of how it operates is the same.

In the Mariner, when you hit the gas to pass at highway speeds or drive up a hill, the relatively weak 133-horsepower engine revs quickly to one of its power peaks — approximately 4,000 rpm or 6,000 rpm — and stays planted there while the CVT does its thing to accelerate the vehicle.

The electric motor lends a hand, and the performance is acceptable, if not fast, but the drone from the engine can wear on you, giving the impression that the engine is working a lot harder than it should be.

It’s a turn-off to some drivers, and a big reason CVTs aren’t widely used. Hybrid drivers expect things to be different, however, so the added efficiency of a CVT is the perfect fit. Toyota uses a nearly identical combination in its lineup, including the mileage-king, Prius.

Aside from all this, the Mariner hasn’t changed a bit during its eco-makeover. It has the same blocky-looking, but easy to use, dashboard; the same reasonably comfortable front seats with more legroom than you get in some full-size SUVs; and the same bearably comfortable rear seats with as much legroom as you’d expect to find in a compact SUV.

One nifty byproduct of having an electric motor on board is an optional three-prong 110-volt power outlet, just like the ones in your home. At $180 it’s not a cheap, but you won’t need to buy any more car adapters for your portable electronic devices, and if you use the Mariner for work or the occasional tailgate party, it’s a convenient feature when you’re parked in the middle of nowhere.

For 2009 Mercury is putting a larger, more-powerful gas engine under the hood of the Mariner and Escape Hybrids, and if you live in the mountains or regularly drive around with a full load of passengers, like a good car-pooling environmentalist should, you might want to hold out for that one.

If you spend most of your time behind the wheel solo, still searching for like-minded save-the-planet friends to drive around with, the current model will suit you just fine.

Better yet, if anyone gives you any grief for commuting alone in an SUV, remember, the Mariner Hybrid comes with a free pass.

Just tell them Al said it was OK, and if they don’t like it, they can take it up with the Nobel committee.

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2008 Mercury Mariner Hybrid

Base Price: $25,765

As Tested: $31,000

Engine: 2.3L inline-4 w/electric motor

Power: 133hp/155hp net w/electric motor assist

Drivetrain: Front-wheel drive w/CVT

MPG: 34city/30hwy

What do you think of the Mariner Hybrid?

Send your comments to foxcarrreport@foxnews.com