Porsche Explains The 911's Wet Mode

What's scarier than driving a high performance car with the engine hanging off the back? Driving that same car in the wet, knowing that the tyres it comes equipped with are probably not the best in slippery conditions. We're talking about the Porsche 911, of course, and it's a car that's been known to bite unsuspecting drivers even on a nice sunny day - let alone on a slippery night. Perhaps that's why Porsche decided to introduce Wet Mode with their latest and greatest 992-generation 911.

The system can detect when the road becomes wet, which first issues a warning to the driver to let them know that aquaplaning and big losses of grip are becoming entirely more likely. Given the calibre of drivers in this day and age, it's a feature that may seem redundant to some but could be enough to slow a less experienced driver down. The method of detection is novel: acoustic sensors in the front wheel housing detect spray coming off the tyres, which allows it to tell if the road is wet even after the rain has stopped (rain sensors need water droplets to hit the windscreen). 

In addition to the warning, the stability and traction systems are primed with specific wet-road calibration, making them react earlier and with less tolerance for wheel slip. The key to keeping a mid or rear engine car under control when losing grip is to react quickly and smoothly - something that sounds like a bit of an oxymoron, but the idea is to control how the mass of the engine travels as you lose and regain grip. This safety system calibration emulates that by detecting as early as possible with less violent interventions to bring the car back under control without overloading the tyres or inducing secondary moments.

The driver is then recommended to switch to a dedicated Wet Mode that primes all the other systems of the car for the conditions. if the driver manually chooses this option, a number of adjustments are made. Most notable is the throttle response and power delivery which is flatter and more progressive, allowing for finer control of the throttle when treading lightly. Some of you may remember that the Renault Megane RS 250 Cup had the same system, accessible through a selection of menus and labelled as Pedal Law; the approach Porsche is taking is fairly similar.

Besides the engine, the aerodynamics are also adapted such that the wing deploys from 90 km/h and more cooling flaps are opened up (we're not entirely sure why the latter is the case, perhaps to induce drag). The PDK transmission is adapted to keep the revs more in the mid-range for better traction and predictability when combined with the flatter throttle response. Even the electronic locking differential is recalibrated to be less aggressive, providing more leeway for the driver to get through a corner. On all-wheel drive models, more power is sent to the front axle for better directional control.

It goes without saying that the more aggressive drive modes like Sport are also locked out for the user. What Porsche has done is electronically augmented what one might call a "wet setup" when tuning a race car or fast road car - many of the elements that are adjusted are what a race engineer would do to make the car more driveable during a wet race. Having it all executed with the push of a button is a great help for a driver of any experience level, even if it may feel like a bit of a crutch at first. Sometimes all you want to do is get home in one piece, and having a car that's easier to drive could be the difference between parking it in your garage or parking it in a ditch.