The McLaren 12C has a secret: The coupe's roof is little more than an aluminum-and-glass toupee that's been Krazy-glued in place with scant concern for structural rigidity. Put another way, the new 12C Spider is essentially as stiff as the fixed-roof car -- without any additional bracing.
Coupe-like rigidity from a roofless chassis is achieved via the large, hollow rails that run down each side of the MonoCell carbon-fiber tub. And for a company that will sell fewer than 2000 cars this year, using the exact same (complex and expensive) chassis for the coupe and the convertible amounts to a manufacturing coup.
A convertible like no other
With no reason to worry about chassis flex, McLaren has also kept the suspension as stiff as the 12C coupe's. That makes this Spider unique among six-figure open supercars, including the 12C's chief rival, the Ferrari 458 Spider. Softening the suspension is standard practice in a coupe-to-convertible metamorphosis, but McLaren needn't make such compromises thanks to its ProActive Chassis Control, which forgoes steel anti-roll bars in favor of interconnected dampers and sophisticated computer controls. The system squelches body roll in turns yet also allows the wheels to move independently over bumps on straights, so not only is the Spider as firm as the coupe, it's also as forgiving. In convertible form, the chassis remains the 12C's greatest attribute, with sharp responses, excellent balance, and supernatural ride quality whether the handling control is dialed to normal, sport, or track. On the 3.4-mile circuit at Spain's Ascari race club, McLaren's Formula 1-derived Brake Steer dissected chicanes, banked turns, hairpins, and changing-elevation corners with such assured aplomb that the 12C started to rewrite our biases. Maybe trading a 40-pound differential for brake-based torque-vectoring isn't such a crazy idea after all.
Spending quality time at speed with a 12C will also alter your understanding of its maker. McLaren's expertise isn't just technology; it's integrating technology with such profound skill that the 1's and 0's translate into nuance and finesse. Coupe or Spider, on road or track, it's a challenge to find serious fault with the 12C.
Quirks and quick fixes
That's not to say there isn't room for improvement. The 3.8-liter twin-turbo V-8 lacks the intoxicating immediacy of Ferrari's normally aspirated engine and the seven-speed dual-clutch gearbox has its moments of suspect logic. In automatic mode, the transmission occasionally places too much faith in the turbochargers and holds its gear at 3000 rpm despite the full-throttle request of the driver. You can also catch it shifting more slowly than an economy car in manual mode if you ask for a big downshift when you're light on the accelerator. And despite McLaren's organizational neuroticism -- er, attention to detail -- there's evidence that the company is still learning when it comes to manufacturing. While we paused at a scenic overlook, a fickle Brit tourist picked the 12C apart for its uneven panel gaps and inelegant weather stripping.
His quibbles hardly registered, though, as we raced up Southern Spain's dreamlike A-369 and marveled that an automaker this green has gotten so much right. Heck, it's possible that by this time next year every McLaren will be assembled with the body quality of a Honda; the folks in Woking have embraced the notion of running changes with uncommon enthusiasm. An all-new engine calibration adds 24 hp to last year's 592-hp output, the loudness of the intake sound tube is now adjustable independent of the powertrain modes, and the throttle reacts to inputs more quickly. Eager to appease the very customers that prompted these changes, McLaren will flash the software updates onto all 2012 cars free of charge. Unfortunately for those owners, the most significant 2013 update involves hardware. A physical button on the exterior now opens the doors with perfect reliability and puts an end to the silly swipe gesture.
A new way of looking at convertibles
Beyond the thrill of exercising 616 hp with the top down, there are a couple of perks to choosing the convertible over the coupe. The nook under the tonneau cover moonlights as a second cargo hold when the top is up, and every $268,250 Spider comes with two small, L-shaped bags tailored to the contours of that space. On a more emotional level, lowering the top opens up a whole new aural experience. The flat-plane V-8's grunt isn't quite as deep as in the coupe, but the turbocharger waste gates take over with a sharp, snare-like rattle every time you back off the gas pedal. And while the roof can be opened or closed at speeds up to 19 mph, the rear window can be lowered at any velocity, creating an uninterrupted path for the engine's soundtrack to reach your cochlea.
Perhaps the only black mark on the Spider's record is a weight increase that raises the curb weight to 3249 pounds. Yet holding the gain to just 88 pounds is a heroic achievement for any convertible conversion. Whereas you can typically assume that the droptop model is a softer car for a softer buyer, you can't think of the McLaren that way. We're not looking to start a trend here, but amid four-door coupes and crossover coupes, we can't help but think of the McLaren 12C Spider as a new kind of automotive oxymoron: the folding-top coupe.
2013 McLaren 12C Spider
Engine: 3.8L twin-turbo V-8, 616 hp, 443 lb-ft
Transmission: 7-speed automatic
EPA Mileage: 15/22 mpg