January 10, 2024

PTM: Porsche AWD Explained

Porsche Traction Management, or PTM, is the proprietary name for Porsche’s modern All-Wheel Drive (AWD) systems. PTM has been developed over the past 30 years to get to where it is today. Porsche’s AWD systems are legendary for their precision and performance, but understanding how they work can be a bit technical. Let’s break it down with a guide:

The Basic Layout of PTM

Imagine your Porsche as a power plant with a central engine. This power needs to be distributed to all four wheels for optimal grip and handling. Here’s how the core components work:

Engine: Generates the power that drives the system.

Transmission: Sends the power to the front and rear wheels via the differentials.

Driveshafts: Connects the transmission to the variable center differential, and delivers power to the front wheels.

Differentials: Distribute the power to each individual wheel and allow for independent wheel speeds during cornering. The front wheels engage via electro-hydraulically actuated multi-plate clutch in the center differential.

The Magic of Differentials

Differentials are the unsung heroes of AWD, ensuring optimal traction and handling. They work by:

  • Allowing each wheel to rotate at different speeds: This is crucial when cornering, as the outside wheels need to travel a farther distance than the inside wheels. Without differentials, the wheels would bind and scrub, causing loss of traction and control.
  • Transferring power to the wheels with the most grip: If one wheel loses traction, the differential can send more power to the wheel with the most grip, providing better stability and control.

Porsche’s AWD Variations

Porsche has offered three different types of AWD systems over the years as the engineers have discovered how to make their systems perform better.

Differential Slip Controlled Drive

The first iteration of Porsche AWD. This system was a full-time AWD system with a transfer case sending 69 percent of power to the rear axle, and 31 percent of power to the front.

Hang-On All-Wheel Drive

Introduced with the 993 Carrera 4 and 911 Turbo, Porsche introduced a brand new AWD system that was both simpler and lighter. The rear axle was directly driven by the transmission, while the front wheels were sent power by a passive viscous coupler that was only activated when slippage occurred.

Porsche Traction Management (PTM)

Found in all modern AWD Porsches, PTM is a fully variable system that can adjust the power distribution between the front and rear axles based on driving conditions. First debuting in the Cayenne in 2002, it was then revised for the 997 which became the standard for which modern PTM is based upon.

The 5 Basic Principles of PTM

Modern PTM is lightning fast and incredibly precise – exactly the kind of qualities you would expect to find in a Porsche-developed system. To achieve optimal results, PTM has been designed with five basic principles that still embody the system today.

  1. Basic Torque Distribution
  2. Guided Control
  3. Slip Controller
  4. Oversteer Correction
  5. Understeer Correction

The Takeaway

Porsche’s AWD systems are complex but incredibly effective. They provide superior grip, handling, and safety in all driving conditions, making them a key reason why Porsches are so renowned for their performance. With the Macan and Panamera sharing the PTM technology, these family-oriented vehicles have best-in-class performance and handling.

Bonus Tips:

Remember, AWD doesn’t defy physics. Drive cautiously in winter conditions and adjust your driving style accordingly. Regular maintenance of your AWD system, including tire rotations and fluid changes, is crucial for optimal performance. I hope this guide has helped you understand how Porsche AWD systems work. If you have any further questions, feel free to contact us!

Source: https://newsroom.porsche.com/en/history/porsche-all-wheel-drive-milestones-lohner-porsche-cisitalia-racing-car-carrera-4-viscous-coupling-porsche-traction-management-ptm-911-turbo-15046.

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