Cars like these appear once every decade or so. When they do, they spark fervor and spectacle with their radical designs and advanced technology. They both benchmark the car industry and show its future. They signify when everything changed. There was the time before the Ferrari F40 and Porsche 959, there was the time before the McLaren F1, and there was the time before the Bugatti Veyron. There was the time before today.

The McLaren P1 and the Porsche 918 Spyder might as well be monoliths sitting in the paddock at Mazda Raceway Laguna Seca. We form loose circles around them, drawing our eyes over their wind-tunnel-formed carbon-fiber exteriors and pointing out their many extravagances: "Look at how tall that wing goes!" "You can lift those magnesium wheels with your fingers!" Both cars make an array of strange mechanical noises -- whines, hisses, groans, and whirrs.

An innocuous email a few months ago led to this day. Ben, the owner of the P1, thought Motor Trend's race-car driver, Randy Pobst, would be pretty fast in his car at this track, but there was only one way to find out how fast. Naturally, we thought it best to have a Porsche 918 and Ferrari LaFerrari join, too, to see which would set the fastest lap time. McLaren was happy to send technical support, and Porsche supplied a 918, but Ferrari refused to grant permission for hot laps and data acquisition to the owner of the car we had lined up.

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The day was no less special. Considering the immense technological investments these machines require and the dramatic differences of the people who build them, it's remarkable that not only have the P1 and 918 arrived at the same year but that they have also settled on a common theme. The supercar of the future has a carbon-fiber tub and body panels. It has its small-displacement, high-revving V-8 with a flat-plane crank, and it's packed between the passenger compartment and the rear axle. It uses a twin-clutch transmission. The brakes are carbon ceramic, the aero active. The horsepower might as well be 1,000. But perhaps best of all, the supercar of the future is a plug-in hybrid that can drive under electric power alone.

Then the philosophies begin to diverge. The P1 relies less on its hybrid system than the 918 does, using it like a 177-hp power-adder that can also offset the sensation of lag from the 3.8-liter V-8's two turbos. Drivetrain simplicity means less weight, but why stop there? You might also not bother with anti-roll bars or a mechanical locking differential. Indeed, the P1 has none of those, relying instead on an electronically controlled hydraulic system to control both roll stiffness and ride height and clever brake intervention to limit wheelspin and help the car turn. McLaren will happily tell you that the philosophies employed here are the same ones banned from F1 for being too effective.

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The resulting weight difference gives the P1 a 347-pound advantage over the 918, but the suspension control also gives the car its coolest feature: Race mode. Press the button on the dash while parked, and over the next 30 seconds or so the P1 lowers itself 2.0 inches, its wing extends 11.8 inches, the roll stiffness increases somewhere between 300 to 350 percent, and so on. In this mode, the P1 can produce 1,323 pounds of downforce at 161 mph, McLaren says. Crucially, it also looks fantastic in photos. The Volcano Orange color helps, too, shifting between deep hues of red and orange depending on the light. Ben calls his P1 -- number 144 of 375 -- the Pumpkin.

The suspension control gives the P1 its coolest feature: Race mode.

This 918 has a name, too: Alice. It's supplied by Porsche North America, which named each of the 918s it owns. (The names are stickered under the rear wing in Comic Sans -- someone has a terrific sense of humor.) Alice is number 134 of 918, making it a real live production car.

If the P1 has the more interesting suspension, the 918 has the more interesting drivetrain. It similarly bolts a 156-hp hybrid motor to its naturally aspirated 4.6-liter V-8, but Porsche figures that if one electric motor is good, two must be better. So in addition to its torque-boosting rear motor, the 918 also has a 129-hp motor on the front axle. The axles don't share a mechanical connection, and the rear tires also steer, which allows for interesting chassis gymnastics. The 918 looks like the larger car in the metal, as it's 2.3 inches longer than the P1 and lacks a low ride-height mode (both can lift their front axles to clear driveways). Porsche has opted for larger wheels and tires than McLaren, an inch taller in diameter, half an inch wider up front, and an inch wider in back. The optional Weissach magnesium wheels ($32,500) drop total weight 33 pounds.

For the sake of fairness, we fueled up both cars at the same pump, and Tire Rack supplied factory-spec rolling stock for both cars. On the P1 went the most aggressive tires owners can get from the factory: Pirelli P Zero Trofeo Rs, which came heat-cycled. The Michelin Pilot Sport Cup 2 is the only tire option for the 918, and Porsche opted against heat-cycling.

Porsche figures if one electric motor is good, two must be better.

Like a children's fantasy storybook, Alice and the Pumpkin set off to lap Laguna Seca.

The production car lap record here is 1:30.97. It will fall today. Pobst set that time last year during Best Driver's Car with a pre-production 918 named Meredith. His familiarity with the 918 means he'll lap Alice first to acclimate to the radical speeds these cars generate.

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The MT team huddles around the 918, rigging it up with a small array of cameras and three data loggers—one primary, two redundant. With the cameras rolling and the loggers logging, I give Pobst the thumbs-up. The radio squawks. "918 on track. 918 on track." Our group has their phones out, digital stopwatches ready.

You can't see much of Laguna Seca's 2.21 miles from the paddock. Occasionally the sound of exhaust reverberates through the hills, maybe the sound of tires squealing, a quick blur of a car.

Then suddenly there's the 918 braking hard for Turn 11, tucking around the corner and then past us, its vertical exhaust pipes screaming, up and up and over the hill leading into Turn 1. Pobst is flat on the throttle at more than 150 mph.

The 918 flies by, and we

hear rumors of 1:29 -- a record.

He pulls in a few times for tire pressure adjustments and to give feedback to the two Porsche reps present. Bleeding-edge performance cars always require special attention and have their own quirks. Hot-lapping these two requires careful monitoring of the battery's state of charge. The electric boost in both roughly matches that of your daily driver's entire engine output; there's no point in pursuing the fastest lap time when it's gone.

Either would be fine for constant lapping sessions with most drivers, but hunting down the fastest lap with a pro requires a different approach: one flyer at full pace followed by a warm recovery lap. Both cars regenerate power quickly, the 918 with braking and engine power, the P1 with surplus engine power alone -- there's plenty to spare.

Pobst flies by again, and there's some excitement from the phone timers. We hear rumors of 1:29.

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When he pulls in, we begin de-rigging the car and digging into the data. Pobst gets out beaming, as one would expect. He says the steering is very quick. "The tail could be easily provoked into a slide," he says. "The car could drift, and the power to all wheels did not necessarily stop it. I enjoy that kind of balance in an all-wheel drive. Like a rear-drive, really. The front-drive was subtle mid-corner but very effective accelerating out of it." Effective, indeed. The data shows a best lap of 1:29.89 with a top speed of 153.7 mph. We're shocked. That's 1.08 seconds faster than the 918 from last year. But combing through the data to find out why will have to wait. There's additional video to shoot and another car to lap.

The day is warming up, and there's much to learn about the car. A McLaren engineer explains a few details to Pobst and gives advice. One bit: Hold down the blue button labeled DRS on the steering wheel on the front straight. This stalls the wing, minimizing drag and letting the car accelerate harder.

All eyes follow the P1 as it rolls from the pits. There's no need for a radio announcement. Its exhaust has an old-school muscle car grumble, deep and low and burbling. The P1 disappears over the hill. Something wicked that way goes.

The paddock is quiet, nervous. If the heavier and less powerful 918 can break into the 1:29s, what can the P1 do with its lower weight, Race mode, and extreme downforce? Some guess into the 1:28s.

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Then, with a flurry of downshifts, the P1 thunders up to 11. Tires squeal as Pobst comes around. The car starts to slide, and you can see Pobst fighting the wheel. He gets it centered and storms over the straight. The engine revs flare up as the P1 goes over the hill -- wheelspin. It happens on the next lap. And again.

The P1 idles back into the pits. The butterfly door lifts up, and there's Randy, wide-eyed and with a huge smile. "Wow, thrilling ride," he says. "There's a lot of drama!" With just 3.8 pounds per hp, the P1 falls into superbike acceleration territory, but with its cleaner aerodynamic profile and four contact patches, it's faster and has more grip. So fast, in fact, that it's the quickest production car we've tested -- I did the quarter mile in 9.8 seconds at 148.9 mph in a development car last year.

The 918 and P1 blaze an

evolutionary trail for the rest to follow.

On the track, that acceleration is all-consuming. "I was so busy I never felt like hitting that little DRS button," Pobst says. "It can spin these very sticky Pirelli Trofeo R tires violently through second and third, a wonderful feeling, frankly."

When he does use the DRS, the data shows him doing 155.5 mph over the hill at Turn 1, but the real shock is that the P1's laps are in the high 1:30s. McLaren people are surprised. Porsche people are surprised. Everyone is surprised. We adjust the pressures, and Pobst heads out again. Everyone's anxiously watching the stopwatches on their phones.

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Pobst comes back in, still beaming. "Throttle control is critical, challenging, and enjoyable with the traction and stability off," he says. "I love a car with more power than tire grip. It just adds to the thrill." The McLaren people change tire pressures. An engineer says the Pirellis take four or five adjustments before they settle. The P1 goes out for more laps and comes in for more adjustments. On goes another set of Trofeo Rs. More laps. More pressure changes. The best the P1 does is a 1:30.71.

Everyone anxiously watches the stopwatches on their phones.

What happened? Warmer afternoon air certainly didn't inhibit the P1's engine, as it out-accelerated the 918 everywhere. Pobst has two theories. One: "The P1 ABS was old-school obvious in its application and felt as though it lengthened brake zones considerably. I kept overrunning the turn-in points in it. This was the primary area where it can be improved, a quicker cycling, smarter, track-ready ABS control system like in real race cars." The second is that the P1 might have trouble applying 904 hp through two wheels, sticky as they may be. "The McLaren could not exit the four slow corners at Mazda Raceway Laguna Seca the way the 918 could, a clear and present contrast," Pobst says. He adds that the 918 is looser than the P1 on entry but the powered front axle allows him to pull out of corners harder and more consistently. It was evident from our view at Turn 11, watching Pobst focusing hard on keeping the car straight; power oversteer looks fantastic, but it's not the fast way around a corner.

How did this 918 gain a second over the record? Meredith, the dark blue 918 that held it, was a preproduction vehicle and exhibited the occasional hiccup. On Pobst's record-setting lap last year, Meredith stopped accelerating over Turn 1 at 140 mph, as if Pobst had lifted off the throttle. Neither Alice nor an earlier 918 development car we tested at Big Willow last year exhibited this behavior. Both cars continued to accelerate past 150 mph, and that accounts for a significant amount of time at Laguna Seca. Further, Porsche reckons the 918 would be even faster with the same effort put into the McLaren's tires and pressures.

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Everyone knew this day would end with one car faster than the other. That car is the Porsche 918. Its clever all-wheel-drive system, talented Michelin tires, and superior braking performance delivered it not only the fastest lap but also a new record for production cars at this track. It is a superlative performance for a superlative car. Although there's undoubtedly some disappointment in Woking, the P1 remains the quickest-accelerating production car we've ever tested, and that wild sensation of speed leaves a deep impression on Pobst. "It was thrilling and satisfying and, yes, made me want even more," he says. "The P1 felt more like a race car than the 918, which was more super street car. The 918 was more civilized on track and in appearance. The P1 is the wild child."

Lap times aside, the magnitude of these cars' accomplishments deserves the most attention. Here we have two plug-in hybrid street cars with EV modes on street tires posting lap times that that would qualify them mid-pack in most sports car races at Laguna Seca. It's when you contextualize their data against "normal" fast cars such as the SRT Viper TA and Chevrolet Corvette ZR1 -- both previous lap record holders here -- that the evolutionary jump these two have made becomes clear. Literally, there's a gap in the acceleration curves where the P1 and the 918 seem to have skipped years of development and technological improvements. They've leaped far into the future, blazing a trail for everyone else to follow.

Superpowers

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Which is the greater superpower: leaping tall buildings in a single bound or having Hulk-like strength? The Porsche 918 and McLaren P1 are basically the superheroes of hyper-performance, and their individual automotive superpowers were on spectacular display at Mazda Raceway Laguna Seca. Among the Porsche's arsenal are all-wheel drive, fatter tires, and bigger brakes; in the McLaren's quiver are greater horsepower and lower weight. Around the slow climbs and quick drops of the circuit's 2.21 miles, the P1 grabbed a brief edge through Turn 1 but instantly lost it to the 918 while braking in Turn 2, though the Porsche certainly never stopped feeling the McLaren's hot breath on its neck. For this duel, we've created an additional analysis: the two cars' speed difference. Under acceleration, the P1 has the edge while the German trumps the Brit when braking. If the graph departs from 0, it means one has an advantage -- upward for Porsche, downward for the McLaren. Crucial to the Porsche's performance is its low-speed advantage, both accelerating and stopping.

Have software that can read .vbt files and want look at the data yourself? Download the files here.

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