Saab XWD, an acronym for Cross-Wheel Drive, is an advanced all-wheel drive system designed by Haldex in partnership with Saab.
Also known as Haldex Generation 4, it is an intelligent permanent all-wheel drive system that can pre-emptively and continuously change torque distribution before wheel slip occurs.
In this video, we can see Saab XWD in Slow Motion on Ice road:
During cruising, the system’s multiplate wet clutch sends a small amount of power to the rear wheels for stability. Should the vehicle’s data sensors determine it appropriate, the clutch, which is located in front of the rear differential, can lock to fully engage rear traction.