What's harder to make, an F1 race car or the road-going McLaren P1? McLaren ought to know, as it makes both. If you ask someone there, such as Mark Vinnels, the head of product development, he'll pause for a second, think, and then say, "The road car."

Why? Consider that the P1 is a rear-drive hybrid with 904 horsepower but isn't penalized with a gas-guzzler tax. Consider that it's mostly carbon fiber, from passenger tub to the five body panels to the mostly naked interior. Consider that its exterior is sculpted primarily for airflow, and that it makes so much downforce (1323 pounds at 160 mph) that McLaren has to adjust the wing at high speed to avoid breaking things. Consider that the P1 uses concepts from McLaren's F1 efforts, many of which (active aerodynamics and suspension, brake steering) were banned from the sport. Consider that the top speed is an electronically limited 217 mph. Consider that it shoots flames.

I consider these things while getting into VP5, for Validation Prototype 5 (of 5), a U.S.-spec Volcano Yellow P1 with 10,319 miles on the odometer. It's the brightest thing at this grey airport, which sits 18.4 miles south of the Bond villain-esque McLaren HQ and which you might recognize from a popular British car show. (Some say they saw a figure in a white driving suit off in the distance.)

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The engine started, and I don't remember much of what followed, other than the feeling of being absolutely consumed. I exited with shaky hands, dribbling expletives and drool.

Here's what I do remember: At the end of our day, when no one was looking, I hopped in the P1 with our VBox data recorder. I slowly drove out of view to the far end of the runway (nothing to see here, folks), activated race mode, waited the required 40 seconds for the suspension to lower 2.0 inches and wing to rise 11.8 inches, and then activated launch control.

Then I was going 160 mph.

Here's what happened: The P1 took 2.6 seconds to reach 60 mph, 4.7 to 100, 6.3 to 120, and then passed the quarter mile in 9.8 seconds at 148.9 mph. Forget the Veyron. The P1 is the quickest production car tested in Motor Trend's 65-year history.

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Now seems like a good time to mention that when you hit the E-mode button, the engine turns off, transforming the quickest production car we've ever tested into a zero-emissions electric car with 6.2 miles of range and acceleration similar to that of a Civic Si. You can plug it in, too. Tiny electric range means the gas engine will be on most of the time. And when it is, the electric motor acts like a 177-hp power adder, offsetting turbo lag by providing torque the moment you touch the throttle. For some theater, you can opt for boost mode, which holds back electric power until you press the cutely named IPAS button on the steering wheel. It feels like hitting nitrous.

Stupefying straight-line acceleration isn't the P1's focus. It was on the checklist, sure, but it almost feels like a byproduct. I like to imagine it was discovered somewhere during development, around the part where, during durability testing, it had to undergo 200 back-to-back launch control runs. (Our sympathies for that test driver's stomach.)

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It passed that test. Why wouldn't it? This is McLaren after all, whose executive chair, Ron Dennis, famously shrank the floor plan of the company's assembly hall a small amount so the tile would fit better. This meticulousness and design logic permeate the P1. Like the 12C, it doesn't have a locking differential because the brakes and stability control system provide ample wheel speed control. Why add the weight? You don't even notice it until you turn stability control off and leave long stripes of 315/30R20 Pirelli Corsa behind.

Same goes for anti-roll bars and downforce resistance bars (or heave springs). Supplant them with a hydraulic system of lines and accumulators and you gain far better control than what an aluminum tube can offer. The P1's roll stiffness, for example, increases 3.5 times when you switch from Normal to Race mode. We weren't able to record the P1's lateral limits, but they felt similar in magnitude to the acceleration. Reaching for them is not as difficult as the performance figures might make you think. It's instead about relearning what you know about the limits of modern performance cars.

The downforce, tires, and brakes take the P1 to territory unknown to street cars. You're conscious of the potential, but the balance and the stability control system let you think with enough time you could reach it. In Race, where I spent the majority of the day (wouldn't you?), the car offers high levels of slip before intervening -- just under half a turn of correction. It's enough to make you feel like you can go to the point of no return and turn around.

My brief time with the P1 felt like leaping blindly into unexplored area. It was like landing on an alien world where you need to reset your preexisting definitions and expectations about the capabilities of cars. The trouble wasn't driving it, but comprehending what was happening.

Why was the P1 harder to make? Because hyperbole isn't supposed to be real.

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McLaren P1 POWERTRAIN/CHASSIS DRIVETRAIN LAYOUT Mid-engine, RWD ENGINE TYPE Twin-turbo 90-deg V-8, alum block/heads VALVETRAIN DOHC, 4 valves/cyl DISPLACEMENT 231.8 cu in/3799 cc COMPRESSION RATIO 8.1:1 BATTERY TYPE Lithium-ion POWER (SAE NET) 727 hp @ 7500 rpm (gas)/177 hp (elec)/904 hp (comb) TORQUE (SAE NET) 531 lb-ft @ 4000 rpm (gas)/192 lb-ft (elec)/664 lb-ft (comb) REDLINE 8300 rpm TRANSMISSION 7-speed twin-clutch auto. AXLE/FINAL-DRIVE RATIO 3.31:1/2.27:1 SUSPENSION, FRONT; REAR Control arms, coil springs, adj shocks, hydraulic anti roll and downforce resist; control arms, coil springs, adj shocks, hydraulic anti roll and downforce resist STEERING RATIO 12.2:1 (est) TURNS LOCK-TO-LOCK 2.2 BRAKES, F;R 15.4-in vented carbon ceramic disc; 15.0-in vented carbon ceramic disc, ABS WHEELS, F;R 9.0 x 19-in; 11.5 x 20-in, forged aluminum TIRES, F;R 245/35R19; 315/30R20 Pirelli P Zero Corsa DIMENSIONS WHEELBASE 105.1 in TRACK, F/R 65.3/63.1 in LENGTH x WIDTH x HEIGHT 180.6 x 76.6 x 46.8 in TURNING CIRCLE 39.0 ft SEATING CAPACITY 2 CARGO VOLUME 4.2 cu ft TEST DATA ACCELERATION TO MPH 0-30 1.2 sec 0-40 1.7 0-50 2.1 0-60 2.6 0-70 3.0 0-80 3.5 0-90 4.1 0-100 4.7 0-110 5.5 0-120 6.3 0-130 7.4 0-140 8.5 0-150 9.9 0-160 11.6 PASSING, 45-65 MPH 0.9 QUARTER MILE 9.8 sec @ 148.9 mph CONSUMER INFO BASE PRICE $1,150,000 PRICE AS TESTED $1,150,000 STABILITY/TRACTION CONTROL Yes/Yes AIRBAGS Dual front, front side, front knee BASIC WARRANTY 3 yrs/Unlimited miles POWERTRAIN WARRANTY 3 yrs/Unlimited miles ROADSIDE ASSISTANCE 3 yrs/Unlimited miles FUEL CAPACITY 16.9 gal RECOMMENDED FUEL Unleaded premium