Originally Posted By: rcy
What about a system that knows when the vehicle is starting from a stop and sends more power to the rear wheels, since they will have more traction? Some Subaru systems do this. Do you consider this proactive. Or the Honda/Acura SH-AWD system that can send more power to individual wheels during cornering?
I suppose an argument could be made for that Subaru (STI?) system being proactive, since it's getting set up for acceleration ahead of time. But one could also argue that it's reactive, because it's only programmed to do that as a response to the driver stopping. If the driver instead throws it in reverse after preparing to launch forward, it has to react again to an input it didn't expect.
It's the same with Honda's system. One could argue that it's proactive because it can set itself up to be beneficial even if the driver does not end up cornering hard enough to actually benefit from it. But one could also argue that it's reactive because it's only programmed to do that as a response to the driver's inputs. If the driver instead suddenly cranks the steering wheel in the other direction, it has to react again to an input it didn't expect.
So I guess one could call those systems both proactive and reactive since they meet both definitions. I'd say everyone wins in this semantic argument! For now, I'll just stick with using active for a general description of that stuff. The Honda system was originally called Active Torque Transfer System (ATTS), and Audi's Active Differential serves the same purpose in the same way. So at least I've got someone on my side!