Add Lotus to the list of luxury and sports car makers offering hybrid models to raise fuel efficiency and reduce greenhouse-gas emissions.

It won't be on the market until the "spring of 2014," says Lotus, but 10 days from now at the 2010 Paris Motor Show, it will introduce a concept for its upcoming Elite 2+2 coupe.

620-hp Elite 2+2 coupe

One of a slew of new Lotuses to be shown in Paris, the Elite will be offered in a gasoline version that uses a 620-horsepower, 5.0-liter V-8 engine powering the rear wheels.

The four-seater coupe weighs 3,600 pounds--light for such a powerful car, as per Lotus tradition--and is said to do 0 to 62 mph in 3.5 to 3.7 seconds.Top speed is quoted at 196 mph.

The optional hybrid transmission, which uses a Kinetic Energy Recovery System (KERS) that generates electricity to power integrated electric motors, brings the car's emissions of carbon dioxide down to 215 grams/kilometer, low for such a supercar.

From Formula 1

KERS systems were originally developed to comply with a mandate for energy recovery devices on Formula 1 cars. In those ultra-quick race cars, where every ounce counts, the weight penalty of a high-voltage battery pack--as used in conventional hybrids like the Toyota Prius--would be unacceptable.

Instead, engineers at Williams developed a system in which regenerative braking was used to power a motor-generator to create electricity to power an electric motor that spun up a flywheel.

Drivers could call on the system for a quick boost of power, whereupon the flywheel's kinetic energy generated current that powered an electric motor whose torque added into that provided by the engine.

Porsche, Jaguar, now Lotus

The system is used on the Porsche 911 GT3 R Hybrid, which will appear in competition in the U.S. for the first at the end of September in the Petit Le Mans race at Road Atlanta. One driver, Patrick Long, who campaigns in a standard Porsche 911 GT3, loves the car's speed.

A slightly different type of KERS hybrid, known as the Flybrid system, is used on a Jaguar XF prototype unveiled last week.

$180K, in 2014?

Lotus is quoting the cost at £115,000, or roughly $180,000 at today's exchange rates.

But many things can change between concept and production, so we'd suggest not writing your check just yet.

[Lotus Cars]