2013 Porsche 911 Carrera Cabriolet: No Limousine Stops
May 13, 2013
Our long-term 2013 Porsche 911's braking ability is outstanding in virtually every way. But there's that word: virtually. The one thing that could be better is the way our car approaches a halt in that tiny window of time just prior to when the tires stop rolling. Ideally you want a jolt-free stop, a result that comes from easing off the brake pedal ever so gently just as the car stops. The car then seamlessly transitions between rolling and stopping. In the trade this graceful halt is described as a "limousine stop."
In the Porsche there are no limousine stops. You get a jolt every time, as if you just got your license and haven't learned any nuance yet. It's impossible to be smooth when stopping this car, and I suspect it has more to do with the PDK gearbox (a transmission I've acknowledged as brilliant) than the brakes.
At some point prior to the stop, the PDK has to decouple the powertrain from the driven wheels. It happens to do this just as you're trying to modulate the brake pedal to achieve the desired smooth stop, and this unloads the engine braking effect, and so you try to compensate with pedal pressure, and you can never get it right in time, and...jolt.
To be fair this is a vanishingly minor niggle. However, Porsche as a manufacturer traditionally nails details of the driving experience such as this one better than pretty much any other automaker. It's part of what makes their cars so satisfying to drive.
Jason Kavanagh, Engineering Editor