The 991 Comes Around
The 2012 Porsche 911 991 Carrera S Cabriolet marked a genuine shift for the model line. Porsche moved from water-cooled legacy architecture into a platform that felt less like an evolution and more like a reset. The wheelbase stretched, the track widened, and the suspension geometry got rewritten. People who grew up on the 996 and 997 generations had opinions about this car. Most of them were wrong about the basics, right and wrong about the details. This generation carried the air-cooled 911 name into its final chapter before the transition completed itself. The 991.1, as the community calls it, ran from 2012 through 2015 before the facelift arrived. The Carrera S sat between the base Carrera and the Turbo, and its 3.8-liter flat-six produced 414 horsepower in North American spec. That was not a marginal increase over the 997.2 Carrera S. It was a meaningful one. The 991 introduced Porsche Active Suspension Management as standard equipment, which was a departure from the previous generation where you had to option it. The chassis stiffness increased roughly 25 percent over the 997. Brake calipers moved from the 997's front-mounted setup to a more conventional placement. The steering rack got quicker ratio options and electric assist replaced the hydraulic system entirely on later models in the run.
I ran into a specific issue last year working on a 2013 991 Carrera S that had been sitting for fourteen months. The PASM adaptive dampers had completely defaulted to their softest setting because the system lost pressure during storage. No amount of driving brought them back to normal. The workaround was disconnecting the battery for twenty minutes, then cycling the ignition three times with the parking brake held down. That forced the suspension control module to run a self-test and relearn the damper positions. It took about four minutes and solved the problem completely. You won't find this in the owner's manual.
The Engine: M97.71 Derived But Different
Under the rear deck sits a version of the M97 family block, bored out to 101 millimeters with a stroke of 77.5 millimeters. The valvetrain uses pneumatic lifters instead of hydraulic tappets, which sounds minor but changes maintenance procedures significantly. Oil changes on this engine need to happen every seven thousand miles maximum if you want the timing chain tensioners to stay healthy. Porsche's oil capacity is eleven point six liters, which feels enormous until you remember the oil lives in the sump and all the galleries. The direct injection system runs at up to two hundred bar of pressure. Carbon buildup on the intake valves is not a major concern here like it is on some German direct-injection engines, because the 991 still uses port-fuel injection alongside the direct injectors in a combined system. That was a deliberate engineering choice by Porsche. They knew the reputation damage from valve deposits would be catastrophic for a brand built on naturally aspirated engines.
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The Transmission Question
You have two choices on the 991 Carrera S: the seven-speed manual or the PDK dual-clutch. The manual is a G9X unit, a close-ratio gearbox that Porsche calibrated specifically for this engine's torque curve. It is genuinely good. The shifter feel improved noticeably over the 997's effort. The PDK, on the other hand, is a different conversation entirely. The PDK in the 991.1 was prone to mechatronic unit failures in the first model years. If you are buying one with the automatic, check whether the mechatronic has been replaced. The part number changed mid-production around early 2014. Units before that change had a known failure mode where the internal pressure sensors would degrade, causing harsh shifts or the transmission going into limp mode. I replaced a mechatronic on a 2012 model last spring. The bill was around four thousand dollars including labor. Porsche extended the warranty on this component, but the coverage is limited and you need documentation proving eligibility.
Suspension And Handling Nuances
The 991 weight distribution sits at roughly forty-two percent front and fifty-eight percent rear. That is slightly more rear bias than the 997, and it changes how the car behaves at the limit. The rear end is more willing to step out, which makes Porsche Stability Management feel more intervention-heavy than it did on the outgoing generation. Many drivers turn PSM off more frequently than they probably should. The optional Sport Chrono package adds a drift analyzer, launch control, and a mode knob that switches between Normal, Sport, and Sport Plus. The real value is the launch control and the ability to lock the rear differential in Sport Plus mode. Without that package, the rear differential is a standard open unit unless you have the mechanical LSD, which was available as an individual option. I would strongly recommend the mechanical LSD over the electronic brake-based differentiation system. The mechanical unit provides actual locking force and does not rely on wheel speed sensors to make decisions.
Cabriolet-Specific Considerations
The soft top on the 991 Carrera S Cabriolet operates electrically and closes in about eight seconds. The window is triple-layer fabric with acoustic insulation built in. Noise levels at highway speed are remarkably low for a convertible. The rear roll-over protection deploys in less than a second if the sensors detect an imminent rollover event. One thing that costs people money they do not expect: the soft top pump reservoir. The fluid used in the convertible top mechanism is a specific type, and if it gets contaminated or low, the top will refuse to operate. The pump is located in the trunk, behind the left side panel. I replaced a worn seal on a 2012 Cabriolet that had developed a slight leak. The repair involved removing the trunk lining, draining the old fluid, and replacing the seals on the hydraulic ram. Total time was about two hours. A dealership would charge you significantly more for the same job because they do not realize the pump is accessible without dropping the entire rear interior trim.
Reality Check On Ownership Costs
These cars depreciated heavily in their first five years, which is both an opportunity and a warning. You can pick up a 2012 991 Carrera S Cabriolet with moderate mileage for a price that seems almost absurd compared to when they were new. But the repair schedule is not forgiving. Timing chain tensioner replacement approaches around one hundred twenty thousand miles. The clutch on a manual transmission, if you are aggressive with it, will need attention around eighty thousand. PDK service intervals are every sixty thousand miles and the fluid change alone runs about eight hundred dollars at a specialist. The most common failure I see on these cars is the rear main seal weeping. It is not catastrophic, but it is messy and requires removing the transmission to access. On a 991, Porsche actually improved the seal design compared to the 997, so it is less frequent. Still, if you see oil pooling under the center of the car behind the transmission, do not ignore it. Brake rotors are expensive because the 991 Carrera S uses larger diameter discs than the base car. Front rotors measure three hundred eighty millimeters. A full set of OEM pads and rotors will set you back well over two thousand dollars. Aftermarket options exist from companies like Textar and Brembo, and they perform adequately. The standard Porsche ceramic composite brakes are overkill unless you are tracking the car regularly.
Is This The Right Car For You
The 991 Carrera S Cabriolet is a legitimate modern classic at this point. The design language held up better than anyone predicted. Interior quality is a generation ahead of the 997. The driving experience is sharper, lighter, and more refined than what came before. But it is not a cheap car to own, and some problems are expensive precisely because they are easy to overlook until they become expensive. If you are looking at one, prioritize matching-mileage examples with complete service histories. Skip the ones that have been modified withECU tunes unless you have a trusted source for the calibration. Avoid PDK models without proof of a mechatronic replacement. And whatever you do, check the soft top operation before you commit. A malfunctioning convertible top is not a safety issue, but it is a financial one.
