The 2021 Buick Enclave no longer offers the twin-clutch all-wheel drive system previously available on the second-generation crossover three-row crossover.
Officially known as electronic twin-clutch positraction (RPO code G99), the advanced AWD system was standard on the Premium and Avenir trim levels of the 2018, 2019 and 2020 Enclaves that were equipped with all-wheel-drive. Lesser Essence trims with all-wheel-drive got a regular AWD system, while the base Preferred trim was available only with front-wheel-drive.
|AWD:N/A||Regular AWD||Twin-Clutch AWD||Twin-Clutch AWD|
- S: Standard
- N/A: Not Available
The system features a self-locking rear axle which transferred power to whichever rear wheel was most able to make use of it. It is essentially an electronic version of the mechanical limited-slip differential, which was invented to improve traction.
On low-traction surfaces such as mud or snow, it’s common for one rear tire to have more grip than the other. This is reported to the vehicle’s ECU by the individual wheel sensors, and power is sent to the wheel which is turning more slowly. This results in improvements in overall grip, with the vehicle being less likely to become stuck.
There is a similar effect on tarmac, though it is less noticeable in a utility vehicle like the Buick Enclave. At high cornering speeds, weight is transferred to the outside wheel, which can therefore accept more power up to a certain point. The positraction system made this redistribution of power possible.
Without a system like this, power is sent to the wheel with less grip in every situation. Wheelspin is much more common, and the likelihood of the vehicle becoming stuck on mud or snow is correspondingly higher.
Now, all 2021 Enclave models that previously featured this twin-clutch positraction system will receive a “regular” all-wheel-drive system.
This is the third time that the twin-clutch all-wheel-drive system has been deleted from a GM model in recent history. As GM Authority exclusively reported in August of 2020, it was dropped from the 2021 Chevy Traverse three years after it had been introduced. The Traverse shares the same long-wheelbase variant of the GM C1 platform as the Buick Enclave.