After more than three years, Porsche has taken the wraps off its first-ever hybrid-electric vehicle, the 2011 Porsche Cayenne S Hybrid. It's one of several models in a totally redesigned version of its controversial but profitable crossover.

But if any brand should have a hybrid, it's Porsche. The world's very first hybrid is widely acknowledged to be the Lohner-Porsche of 1902, created by 27-year-old engineer Ferdinand Porsche, who founded Porsche AG after the Second World War.

Lohner-Porsche series hybrid

Lohner-Porsche series hybrid

Porsche Cayenne Hybrid logo

Porsche Cayenne Hybrid logo

Lighter, more efficient

The Porsche hybrid will be unveiled as part of the 2011 Porsche Cayenne range at next week's Geneva Motor Show. Its first U.S. appearance will be at the New York Auto Show in April.

Like its platform mate, the redesigned 2011 Volkswagen Touareg--which also has a hybrid model--the 2011 Cayenne is lighter (by almost 400 pounds). And its range of engines offers far better fuel efficiency than its 2003-2010 predecessor.

You can still have a V-8

But unlike the Touareg, which will move entirely to V-6 engines for U.S. versions, the new Porsche Cayenne hangs onto its V-8 options. The entry-level model offers a base 300-horsepower, 3.6-liter V-6, paired with an eight-speed "Tipotronic" automatic transmission.

Next in line is the Cayenne S Hybrid model, which gets more power (333 hp) out of a smaller 3.0-liter V-6, courtesy of supercharging. It is paired with a 34-kilowatt (47-hp) electric motor that sits between the engine and the eight-speed automatic.

Together, the engine and the motor generate 427 foot-pounds of torque at a low 1,000 rpm, which could make the Cayenne S Hybrid the king of suburban stoplight racing.

97-mph "sailing"

Porsche had previewed the Cayenne Hybrid's "sailing" ability, but the production version can switch off its engine at up to 97 mph under light load or during deceleration. This contrasts sharply with most hybrids, which use electric power only at low speeds.

Porsche says the Cayenne S Hybrid will accelerate on electric power alone up to 37 mph, though we suspect that's not under full throttle. As in all full hybrids, the electric motor supplements the gasoline engine's output, with the blend of the two power sources optimized for lowest fuel consumption.

The 2011 Porsche Cayenne S Hybrid uses a nickel-metal-hydride battery pack located under the rear seat. Porsche did not specify its energy capacity, though it is likely to be between 1 and 2 kilowatt-hours.

Most efficient model

For the European market, Porsche cites the Cayenne S Hybrid emits just 193 grams of carbon dioxide per kilometer. That translates to 28.3 miles per gallon, making it Porsche's single most fuel-efficient model.

By way of comparison, the most efficient model of today's 2010 Cayenne, the base version with a 290-hp, 3.6-liter V-6, is rated by the EPA at 14 mpg city, 20 mpg highway.

While 28 mpg pales against the 50 mpg rating of the 2010 Toyota Prius hybrid, those two cars are simply never cross-shopped. For Cayenne buyers who want to go green while retaining Porsche performance, the new hybrid crossover is the way to go.

2011 Porsche Cayenne

2011 Porsche Cayenne

About those V-8s...

As before, the two top-of-the-line models are the Cayenne S, with a 400-hp, 4.8-liter V-8, and the Cayenne Turbo, with a 500-hp twin-turbo version of the same V-8. Porsche says each of these engines uses 23 percent less fuel than its counterpart in the old model.

At least in Europe, all three engines will be fitted with an Automatic Start-Stop function that switches the engine off at rest.

Longer but visually more compact

While the 2011 Cayenne is almost 2 inches longer than the previous model, most of it in the wheelbase, it has been styled to look more compact and less aggressive and intimidating. It rides lower, and the front end is less bluff.

Inside, the classic Porsche set of five round instruments in the cluster is supplemented with a high-resolution circular screen that displays information on everything from vehicle operating data to navigation system maps.

The two V-8 models, the Cayenne S and Cayenne Turbo, will reach U.S. dealers in July. The base V-6 model and the Cayenne S Hybrid will follow this fall, meaning that Porsche's hybrid will beat its Touareg Hybrid counterpart to market by a year or so.