In a world where driving a big gas-guzzling sport-utility vehicle has suddenly become uncool, the 2010 Cadillac Escalade Hybrid offers its owners a way to show the world just how environmentally friendly they really are. But is driving this green-tinged version of Cadillac's wildly popular yet politically incorrect land yacht really a wise and responsible choice? Well, the answer depends on what you're comparing it to.

To be sure, the Escalade Hybrid does manage to post better fuel economy numbers than its conventionally powered Cadillac SUV siblings. Its two-mode hybrid powertrain, which it shares with its Chevrolet and GMC cousins, combines a beefy V8 engine with two electric motors that can actually propel this gussied-up truck at slow speeds in all-electric mode. The system also incorporates several other fuel-saving bells and whistles to deliver surprisingly decent fuel economy, at least by full-size SUV standards.

While that upside may sound appealing, it comes at a cost. Buyers will have to get used to the powertrain's myriad quirks, from a range of odd noises to a surging feeling when you step on the brake pedal. If your primary reason for buying a full-size SUV is to tow a large trailer, you should also be aware that the hybrid version's towing capacity is 2,500 pounds less than that of the regular Escalade. Finally, there's a literal price to be paid for assuaging your guilt about driving such a supersized luxury vehicle, as this hybrid's MSRP is roughly $5,000 above that of the comparably equipped standard Escalade.

All of which leads us to encourage shoppers to take a hard look at all their options before they sign on the dotted line. The midsize Lexus RX 450h crossover is less roomy and capable, but it does provide significantly better fuel economy. The diesel-powered Audi Q7 TDI drives more like a normal vehicle, has comparable fuel economy numbers and greater towing capacity. The related and similar Chevrolet Tahoe Hybrid and GMC Yukon Hybrid, meanwhile, can be had for thousands less than the big Caddy. If you still have your heart set on the 2010 Cadillac Escalade Hybrid, know that it will provide a luxurious hybrid experience. Just remember that a clear conscience doesn't come cheap.

The 2010 Cadillac Escalade Hybrid is a full-size luxury sport-utility vehicle that's now offered in two trim levels, including a new top-of-the-line Platinum model.

Even base models are well equipped with a long list of upscale standard features, including 22-inch chrome-clad wheels, xenon headlights, a sunroof, a roof rack, a power rear liftgate and rear parking assist. Inside are all the expected luxury amenities, including leather upholstery, heated and ventilated power-adjustable front seats with memory settings for the driver seat, tri-zone automatic climate control, a navigation system with real-time traffic info, a back-up camera, Bluetooth and OnStar. A rear-seat video entertainment setup with a drop-down screen, a 115-volt AC power outlet and a 10-speaker Bose surround-sound system with a six-disc CD/MP3 changer and satellite radio are also standard.

Step up to the Platinum model and you get distinctive LED headlight elements, a sophisticated Magnetic Ride Control suspension and power-retractable running boards. Interior upgrades include a heated steering wheel, power-release second-row seats, heated and cooled cupholders and dual video monitors mounted in the back of the front headrests.

Power for the 2010 Cadillac Escalade Hybrid comes from GM's two-mode hybrid system, which consists of a 6.0-liter V8 paired with two 60-kilowatt electric motors and an onboard battery pack. Total output is 332 horsepower. The combination is intended to deliver maximum miles per gallon in everyday driving while still offering sufficient muscle to tow trailers up to 5,800 pounds, something few other hybrids can claim.

The two-mode hybrid powertrain can accelerate this 5,700-pound SUV up to 25 mph using battery power alone. The system also incorporates several other fuel-saving technologies, including a cylinder-deactivation feature that essentially turns the big V8 into a less thirsty four-cylinder under light-load conditions, such as when cruising on a level freeway.

The unique automatic transmission uses a continuously variable design that allows the engine to operate in its most efficient rpm range. The extraordinarily complex unit also features four fixed gears that come into play primarily when towing or hauling heavy loads. Both rear- and all-wheel-drive versions are available. EPA fuel economy estimates for the 2WD version are 21 mpg city/22 highway and 21 mpg combined, a slight increase over last year's model.

The Escalade Hybrid's list of standard safety features includes antilock brakes, traction control, stability control, side curtain airbags that cover all three rows of seats and the OnStar emergency communications system. A redesigned internal door structure adds an extra measure of protection in broadside accidents.

In government crash tests, the Escalade Hybrid earned a top five-star rating for protection of front occupants in head-on collisions. Side-impact tests hadn't yet been performed as of this writing, but last year's model still earned a five-star rating for both front and rear passenger protection.

You don't have to drive the 2010 Cadillac Escalade Hybrid very far to discover its split personality. At low speeds, where it can motor along in all-electric mode, this big truck's interior seems almost serene. At higher speeds, though, you'll hear the various sounds of the hybrid powertrain at work while the ride quality suffers from the 22-inch wheels and low-profile tires that transmit every bump in the road directly to your backside.

The powertrain works well enough, though the only part of its operation that feels truly seamless is when the cylinder deactivation system automatically shuts down and restarts half the engine's cylinders. The regenerative braking system, which helps recharge the hybrid system's battery pack, is particularly distracting, as it gives the brake pedal a surging feeling that makes it difficult to come to a smooth stop.

The 2010 Cadillac Escalade Hybrid coddles passengers in the same stylish surroundings as the conventionally powered versions. The posh cabin is done up in soft leather upholstery and top-quality materials and features controls that are well-placed and intuitive to use. Standard second- and third-row benches provide seating for up to eight passengers. Unfortunately, the comfy second-row captain's chairs offered on the regular Escalade aren't available here.

The interior's biggest weakness is the 50/50-split third-row seat. Leg-room is scarce, making the way-back best suited to preteens. The fact that the seat doesn't fold into the floor also means wrestling each 60-pound section out the rear hatch and then finding a place to store them when you need additional cargo space. Once you get the third-row removed and the second-row seatbacks folded down, however, you'll find a cavernous 109 cubic feet of cargo room.