In an era where fuel efficiency is environmentally chic, the 2011 Cadillac Escalade Hybrid offers prospective owners of a luxury sport-utility the promise of full-size utility that's socially acceptable. But whether or not this big Caddy makes sense (from either a fiscal or environmental perspective) is an equally important consideration.

On the asset side of the ledger, the full-size 2011 Cadillac Escalade Hybrid is certainly more fuel-efficient than its traditional counterpart -- an estimated 5-7 mpg better, in fact, depending on two-wheel-drive or four-wheel-drive drivetrain and conditions. The two-mode gas/electric powertrain system (shared with similar vehicles from Chevrolet and GMC) is particularly effective in low-speed urban driving, where the two electric motors can operate independently under light load conditions. A 6.0-liter V8 kicks in to deliver more power when accelerating, pulling a heavy load or just traveling at high speed. Cylinder deactivation for the V8 enhances fuel economy, regenerative brakes recharge the batteries and the automatic transmission makes the whole business of mixing the power from the electric motors and the V8 relatively unobtrusive.

There are some liabilities to consider as well. You'll have to get used to the powertrain's mildly eccentric manners, as the transmission responds a bit lazily under full power and the brake pedal delivers a surging sensation. Those seeking maximum performance and heavy-duty towing capability might also find the Escalade Hybrid's 332-horsepower output and 5,800-pound towing limit insufficient for their needs, even as it suits a wide span of applications.

There's no question that the hybrid saves gasoline compared to a standard Escalade, but as with every hybrid, the added cost of purchase for the hybrid means that you feel the benefit in your heart, not your pocketbook. In this case, the price difference is about $10,000 over the standard. The 2011 Cadillac Escalade Hybrid has no competition from brands other than GM, although the smaller 2011 Lexus RX 450h hybrid and 2011 Porsche Cayenne Hybrid are reasonable alternatives as long as towing isn't required. The diesel-powered 2011 Audi Q7 TDI and 2011 BMW X5 xDrive35d are also fine alternatives.

The 2011 Cadillac Escalade Hybrid is an eight-passenger, full-size luxury sport-utility vehicle offered in two trim levels: base and top-of-the-line Platinum.

Base models are well equipped with 22-inch alloy wheels, an adaptive suspension, xenon headlights, sunroof, roof rack, remote start and a power rear liftgate. Inside the cabin you'll find all the expected amenities, including leather-trimmed seating, heated and ventilated power front seats with driver memory, second-row 60/40-split-folding bench seat, a removable third-row 50/50-split bench seat, power-adjustable pedals, tri-zone automatic climate control, Bluetooth and a navigation system with real-time traffic. Also standard are a rear-seat DVD entertainment system, a 115-volt power outlet and a 10-speaker Bose surround-sound audio system with a six-CD changer and satellite radio.

The Platinum model adds LED headlamps, a unique front fascia design, power-retractable running boards, premium leather upholstery, heated and cooled cupholders and dual rear monitors mounted in the front headrests for the rear-seat entertainment system. The power-retractable assist steps are also available on the base model.

The Escalade Hybrid is powered by a 6.0-liter V8 (E85 compatible) working in conjunction with a battery pack mounted under the second-row seat and a pair of 60-kilowatt electric motors located inside the unique automatic transmission. The transmission can operate with continuously variable gearing to allow the engine to work in its most efficient rpm range. When heavy towing or hauling is required, four fixed gears come into play. Combined, this powertrain produces 332 hp and 367 pound-feet of torque and it can be matched with either rear-wheel drive or 4WD. In Edmunds performance testing, the Escalade Hybrid went from zero to 60 mph in 9.3 seconds; the regular Escalade does it in 7.5.

The Escalade Hybrid can accelerate to nearly 30 mph using only the electric motors, while the V8 kicks in when necessary under greater loads or at higher speeds. A cylinder-deactivation system helps reduce fuel consumption, while regenerative braking replenishes the batteries while coasting or stopping. Estimated fuel economy is excellent for a large truck-based SUV at 20 mpg city/23 mpg highway and 21 mpg combined with rear-wheel drive or 4WD.

The 2011 Cadillac Escalade Hybrid is an outstanding performer in safety testing, and features standard antilock disc brakes, stability control, traction control and head curtain airbags for all three rows. Other advanced safety features on the Escalade Hybrid include a blind-spot warning system, rear parking sensors, a rearview camera and OnStar communications.

The 2011 Cadillac Escalade Hybrid exhibits two distinct personalities depending on your motoring mode. At low speeds under light loading, this Escalade can travel in electric-only fashion, which makes for an especially peaceful cabin atmosphere devoid of mechanical vibration and noise. At higher speeds, though, you'll hear the various sounds of the hybrid powertrain at work, while the ride quality suffers from the heavy 22-inch wheels and stiff low-profile tires, which transmit every bump in the road directly to your backside.

The cylinder deactivation system goes about its work seamlessly, as it automatically shuts down and restarts engine cylinders when appropriate. The regenerative braking system takes some getting used to, however, as it gives surging feedback through the pedal as you attempt to come to a smooth stop.

The Cadillac Escalade Hybrid's cabin is nearly identical to that found in the conventionally powered version, boasting a stylish contemporary design with top-quality materials and finish. The layout of its controls is straightforward and their operation is intuitive, including the standard navigation system.

There's room for as many as eight, but the rearmost seats offer cramped legroom for all but small passengers. When it comes time to load up with cargo, those 50/50-split third-row seats also don't fold away conveniently like those in competitors; they are heavy and awkward to remove, and must be stored elsewhere. Once out, though, there's 109 cubic feet of maximum cargo space available.