It was doomsday weather in Stuttgart. The temperature gauge read minus two degrees Celsius (28 degrees Fahrenheit) as the swollen skies emitted a mix of rain, sleet, and snow. Could it be that the whole adventure was in jeopardy? The day before, Frank Walliser, the Porsche 918 Spyder's high-strung project leader, had called an emergency meeting. There was no way that this triple-hearted roadster could be unleashed in such adverse conditions on uncompromising, low-profile summer tires. Officially, Porsche does not yet offer winter rubber for the 918. Unofficially, however, a friend of a friend of Walliser's who works in the prototype shop produced a set of black wheels shod with brand-new Pirelli Sottozero winter tires. That promptly led to another minor complication, namely the need to find space for four wheels with summer tires, not to mention the noncollapsible, four-foot-long torque wrench required to mount them.

Despite these snarls, the factory gates opened promptly at 10:30 a.m. and released a highly exclusive three-car convoy: first out was the Cayenne chase car with driver, photographer, and luggage; second in line was the chrome blue (a $63,000 option) 918; and third was a Volkswagen Touran minivan driven by a chipper mechanic who would swap the Pirellis for ultra-high-performance Michelin Pilot Sport Cup 2 tires at the end of day one.

It takes about fourteen hours to drive nonstop from Stuttgart to Valencia, but we chose the scenic route, which was 1082 miles long and called for 22 hours and 48 minutes of wheel time. My passenger was Sebastian Ruger, a thirty-one-year-old whiz-kid engineer who knows a lot about hybrids and almost everything about the 918. The low, wide, and outlandish two-seater commenced the first leg of the journey in E-Power. In this mode, the two electric motors (one for each axle) whir and hiss a happy duet, which sounds unexpectedly subdued from inside the car and catches pedestrians by surprise. In tandem, the compact power packs muster 286 hp and an impressive aggregate torque of 398 lb-ft. Depending on one's driving style, E-Power offers a maximum zero-emissions range of eighteen miles or a top speed of 93 mph.

On the entrance ramp to the A81 autobahn, a bomb suddenly dropped on our acoustic idyll as the V-8 engine entered the scene like a bat out of hell, loud and harsh and furious. Up to 3000 rpm, the angry, flat-crank, direct-injected 4.6-liter V-8, which is a direct descendant of the RS Spyder racing car's powerplant, sounds rough and raucous. Between 3500 and 6500 rpm, the gasoline feed, firing order, and valve timing finally agree on a slightly smoother rhythm and pace. But it's only from 7000 rpm to the cutout at 9150 rpm that one gets the full hammer effect that also harks back to its race car roots. "In essence, the 918 is a street-legal track tool," says vehicle development leader Eugen Oberkamm. "This applies not only to the drivetrain, but also to the chassis, the steering, and the brakes."

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Too true. The racing seat makes you painfully aware of your love handles, the racing suspension vigorously kickboxes the occupants of the cabin, and the racing brakes decelerate with unabashed grinding noises. The visibility to the rear is also race-car-like, compromised by all those gills and louvers and the XXL wing. The noise level at highway speeds matches a race car for pungency and persistence. Fuel consumption, on the other hand, is more akin to the modesty of a family sedan. Our observed average of 22 mpg was not bad at all for a 214-mph supercar. Depleting a full load of electric juice is dead easy: just ignore the detent in the throttle pedal or push the red "hot-lap" button -- and don't forget to brace yourself. Restoring the energy to its 6.8-kWh peak is equally simple: keep the engine spinning at medium revs for about fifteen minutes in Sport mode -- or better still in Race -- and the green dots will duly light up again.

Lyon, France, welcomed us with ankle-high speed bumps, narrow lanes, and the tallest curbs this side of the Eiger's north face. Although tackling the down ramp to the hotel parking garage was a thirteen-minute nerve-wrecker (even while employing the front-axle-lift system), we successfully completed the slalom course and found the solitary charging point thankfully unoccupied. Whereas a high-speed wall charger would have performed the act in twenty-five minutes, hooking up the car to a (s)low-voltage charger extended the process to about four hours. The batteries always keep a 25 percent emergency charge -- unless you make an impromptu detour to the racetrack, where the entire energy reservoir can be depleted at a push of the hot-lap button. Although the E-Power reservoir was tapped whenever it made sense, we nonetheless had to make four stops to fill the 18.5-gallon fuel tank with a total of

56 gallons of premium unleaded.

The next morning, S GO 9182 followed the river Rhone south in whisper-quiet fashion, elegantly swooshing past slower traffic, repeatedly soaking in applause and thumbs up. When fully charged, battery power alone can whisk the 918 from 0 to

62 mph in a brisk 6.2 seconds. Twelve miles down the road, the black box summoned Hybrid mode, signaling that the V-8 will now cut in and be phased out according to throttle orders. Not sufficiently inspiring? Then twist the thumbwheel one notch clockwise into Sport, and try to suppress a big smile when the powerplant grabs you by the neck and tacks your torso to the seat. In Race, the Porsche morphs into a real road rocket, and the ultrafast urge is matched by an even more aggressive shift strategy. The seven-speed PDK dual-clutch automatic hammers the gears through the gate like a firing pin on steroids, the electric motors howl breathlessly at their ambitious redline, the V-8 keeps bursting noisily into brief charging spells. This car runs concerted attacks on your senses. It dries your throat, moistens your palms, and fills your nose with the sweet smell of fast-flowing electrical current. In a way, it even reduces carbon-dioxide emissions by making you hold your breath in a mix of astonishment and awe.

The arrow-straight and suspiciously empty Autoroute du Sud is the perfect place to check out the infotainment system. We like the comprehensive content, the quick response time, and the clever ergonomics. We don't like the reflections on the shiny screen, the marginally intuitive coordination of the two monitors, and the lack of any haptic feedback. Rolling at a steady 80 mph through radar-infested territory, we killed time rating the Burmester sound system (sensational, and it doesn't even cost extra), the "authentic" leather seats (but are they really $26,000 nicer than the smoother standard leather?), the body-color ignition key to the left of the steering column (why does the wheel telescope but not tilt?), and the auxiliary electric heating (a whopping $6000). Despite the numerous extras, our 918 still lacked the heavily promoted Weissach package, which adds an astonishing $84,000 to the grand total while taking out about ninety pounds of weight. We applaud the achievement, but a similar effect could be reached by buying this driver $1000 worth of Weight Watchers vouchers.

The most demanding section of the entire voyage was the winding coast road between Perpignan, France, and the Spanish border. Although the pavement is narrow, bumpy, and dotted with blind crests, the 918 tracked with the precision of a fighter jet, clung like a magnet to the tarmac sprayed dark gray with mist from the Mediterranean Sea, and decelerated like an accordion, only to reach out for the next straight with expandable elasticity. As soon as the hinterland opened up and the menacing rock faces gave way to rolling hills, the Porsche readily beamed us into a parallel universe with relentless forward thrust. The 2.6-second acceleration from 0 to 62 mph very nearly ended in cardiac arrest, and the speedometer showed 124 mph a mere 4.7 seconds later. Scared by my own courage, I hit the brakes and immediately wished for a four-point belt, stronger forearms, and eyeballs capable of staying inside their sockets. This mind-boggling, energy-squashing performance comes via carbon-ceramic discs the size of manhole covers, custom Michelin tires boasting a top-secret compound, and the riveting regeneration performance of the hybrid braking system, which can pull up to 0.5 g.

We approached Barcelona in balmy weather that felt more like early June than late November -- high time to convert the coupe into a spyder. Even with the roof stowed in the tiny (3.9-cubic-foot) cargo bay, the carbon-fiber body feels as if it has been hewn from solid. The downside to this granite-like rigidity is a rock-hard suspension that feels like it could loosen fillings. Only professional masochists would dare to switch the damper calibration from Have Mercy (standard) to Last Rites (sport). The push of a button will also freeze the large tail rudder for either maximum downforce or maximum speed. Even with the energy packs depleted, the plug-in supercar can top 200 mph, but Spanish jails are damp and cold, so we didn't even try. Through tunnels, 90 mph in third gear was enough to crack the plaster and cause paint chips to drop from the ceiling long after the villain had vanished.

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We arrived at el circuito Ricardo Tormo on the western outskirts of Valencia in time for a quick trackside lunch. Were we ready to put this Porsche to the real test? Sort of, except that the guy in the leading 918 kept pulling away while messieurs Kacher and Ruger were still debating brake points, turn-in points, and gearchange points. Sadly, all it takes to put your driving skills into perspective is one fast lap with Walter Rohrl, who ran the entire track in D and still got to the finish line light years before the distant number two. Lesser mortals clearly need more time to practice, and eventually we did learn to late-apex most corners, to step on the gas early, to anticipate the dialogue between rear-wheel-drive dominance and front-wheel-drive support, to brake

eerily deep into certain bends, to open up the steering much sooner, and to pay attention to the tires rather than understeer into oblivion and thereby convert the stern-faced minders in their brand-new black outfits into lifetime enemies.

Although the track closes at 5 p.m. sharp, we refused to say good-bye to our travel companion just yet. Instead, we pointed the Porsche's low-slung nose toward the open road one last time, through local villages and onto the wide-open barren plains, which glow in different shades of brown, amber, and gray. Although I am strapped to more than $900,000 worth of supercar, the fear factor has shrunk to 911 GT3 levels since we left Zuffenhausen less than three days ago. The 918 Spyder may not be as easy to drive as a 911 Turbo, but it certainly is not a naked razor blade on wheels, either. The difference between the standard model and the Weissach edition we briefly drove on the track is marginal unless you're a pro. Porsche will, however, wrap the Weissach edition in matte black, Martini Racing livery, or the striking Salzburg Racing design, at no extra cost.

Ferrari sold all 499 LaFerraris even before the first car was completed, and all 375 McLaren P1 coupes are also spoken for. Porsche intends to manufacture 918 units of the 918, but so far only two-thirds of the cars have customer names attached. Is this a deja vu of the Carrera GT, which found a mere 1270 takers despite a production target of 1500 units? "No, I don't think so," says R&D chief Wolfgang Hatz. "First test drives have only just begun, and as soon as word gets out about the breakthrough dynamics and the unique engineering concept, the 918 will sell out quickly."

Just in case you are in the market for one of these rare automotive dream tickets, bear in mind that there are two different seat choices (standard or racing buckets), that plug-in charging really is only icing on the cake, and that in real life, this car is so much more than the sum of its parts. Although it's packed to the detachable roof with extraordinary technology, the Porsche we lived with for three days was not an unapproachable monster machine. Quite the contrary: this is a thrilling and surprisingly unpretentious blend of supercar and race car. It's also a vision of the future.

2014 Porsche 918

Base Price:$847,975

Engine: 32-valve DOHC V-8/plug-in electric hybrid

Displacement: 4.6 liters (280 cu in)

Power: 608 hp @ 8700 rpm

Torque: 390 lb-ft @ 6600 rpm

Motors: Two permanent-magnet AC synchronous

Electric output: 129/156 hp (front/rear axle)

Batteries: 6.8-kWh lithium-ion

Total output: 887 hp

Transmission: 7-speed automatic

Drive: 4-wheel

Steering: Electrically assisted

Front suspension: Control arms, coil springs

Rear suspension: Multilink, coil springs

Brakes: Vented carbon-ceramic discs

Tires: Michelin Pilot Sport Cup 2

Tire sizes F, R: 265/35R-20 (95Y),

325/30R-21 (104Y)

L x W x H: 182.8 x 76.4 x 45.9 in

Wheelbase: 107.5 in

Track F/R: 65.5/63.5 in

Weight: 3715 lb

Weight dist. F/R: 43/57%

0-60 mph: 2.5 sec

Top speed: 214 mph

Electric-only 0-62 mph: 6.2 sec

Electric-only top speed: 93 mph

Electric range: 18 miles

Charge times: 7 hours at 120V,

2 hours at 240V, 0.4 hour at 400V

Will the 918's hybrid powertrain go, too?

Between 1970 and 1998, Porsche scored a record sixteen overall wins at the 24 Hours of Le Mans. Thanks in part to the superfast 917 of the early '70s, Porsche became synonymous with France's storied endurance race.

Porsche ended its prototype sports car effort after its dramatic win over Toyota in the '98 24 Hours, and in the years since, Audi has dominated the LMP1 class. Shortly after it unveiled the 918 RSR concept at the 2011 Detroit auto show, Porsche announced that it would return to Le Mans with an LMP1 prototype sports car (and join the nascent World Endurance Championship). Speculation is that the LMP1 car will be heavily based on the roadgoing, hybrid-powered 918 Spyder.

The team will run two WEC LMP1 cars, with Timo Bernhard, Romain Dumas, and Neel Jani as works drivers and testers Marc Lieb and Brendon Hartley trying out for two more spots. And then there's Australian Formula 1 veteran Mark Webber.

He isn't the first retired F1 driver to go to Le Mans, but he may be the most enthusiastic. Webber jumped into a Porsche LMP1 test car at Portugal's Algarve circuit a few weeks before his F1 contract with Infiniti Red Bull had officially expired.

Webber first raced Le Mans in a GT1 Mercedes-Benz in 1998 and '99; in '99 his car took air and crashed, both in qualifying and on the warm-up lap. He began his F1 career in 2002, racing for Minardi, Jaguar, and Williams before joining Red Bull Racing in 2007. From his first victory at the 2009 German Grand Prix, the year Sebastian Vettel became his teammate, through last year, Webber scored nine F1 victories, including two at Monaco. Although Vettel won four championships in the same period, there's little doubt that Webber was more popular with fans. His 2013 season was his toughest, with two poles and eight podiums but no wins. Now, joining Porsche at age thirty-seven, Webber's racing career may just be getting started. - Todd Lassa