For the rich and green, the Porsche 918 Spyder hybrid

Main Line Porsche president Bob DiStanislao can't stop bragging about the fabulous gas mileage on Porsche's super sleek new 918 Spyder.

"It's incredibly efficient, the distance this car can go on a liter of fuel," he said. "It's the most energy-efficient sports car Porsche has ever made."

Think about it:

Even at the premium gas price of just under $3 a gallon, and with an 18.5-gallon fuel tank, the hybrid can speed about halfway across the continent (soaring to 60 miles per hour in 3.2 seconds) on $60, or about 78 miles per gallon.

What a bargain.

But please, Bob, will anyone who can afford the German automaker's $630,000 masterpiece of automotive engineering be counting on fuel savings to offset the cost?

"It's less about buying a car and more about buying a work of art and a work of engineering," DiStanislao said.

The $630,000 figure is attributed to Porsche sources; there's been no official confirmation of the price.

Unlike a Picasso, the Spyder won't likely hang above the sofa, but DiStanislao pointed out that even a $630,000 roadster can appreciate in value.

For example, he said, before being popularized in the movie Ferris Bueller's Day Off, an average 1961 Ferrari 250 GT Spyder California sold for less than $10,000.

In May 2008, the car commanded a jaw-dropping $10.9 million at a vintage car auction in Italy.

DiStanislao said about five of his customers have already put down $5,000 deposits on the 918 Spyder - and that's before Porsche AG has actually committed to produce the car, which it unveiled at the Geneva Auto Show in March.

Porsche said it needs 1,000 sales pledges to produce the car. So far, 2,000 people worldwide signed nonbinding agreements to grab one as soon as it rolls off the assembly line at Porsche's main plant in Stuttgart-Zuffenhausen.

"The 918 is definitely going to sell," said longtime Porsche salesman Eric Exley at Don Rosen Imports.

In the mid-2000s, Exley sold five of the 918 Spyder's pricey predecessor, the Carrera GT. Fewer than 1,300 were produced, with just six allocated to the Conshohocken dealership.

The Carrera GT's carried a price tag of more than $440,000. Two of Exley's customers bought two Carreras each, and one of them already has plunked down a deposit on the 918 Spyder.

"The fact is that there are some very wealthy people, so wealthy that they'll buy it no matter what the price," he said. "If Porsche decides to produce 1,000 cars, they'll sell every one. There's still plenty of money around."

Porsche could use a boost.

Its North America deliveries fell 18 percent to 15,592 units in the nine months through April. Sales in the United States, Porsche's biggest single market, slumped 40 percent last fiscal year to 19,024 cars and SUVs.

Name: Porsche 918 Spyder
Top speed: 198 m.p.h.
Engines: V8 combustion, maximum 500 horsepower and 9,200 r.p.m.; and electric motors on the front and rear axles
Driving modes: Electric only; hybrid-electric and V8; sport hybrid; race hybrid
Electric motor traveling range: 16 miles
Weight: 3,285 pounds, or $191.78 per pound
Battery: Lithium-ion
Seats: Two
Body shell composition: Plastic reinforced with carbon-fiber; also magnesium, aluminum

SOURCE: Porsche AGEndText