Ted_@_Landau_Ford_Lincoln

So latest Fusion AWD system seems better than a 100% reactive one.

 

I think the key is what you stated: that it is "reacting" to changes in steering angle and throttle - so in this respect it works for 'everyday driving'. Taking that fast corner, "flooring it" from a standstill, etc... will engage immediately if this works as Ford says.

That's exactly how it feel... immediately engagement. the only slip you feel is when you accelerate at a rate that's enough to break traction on all 4 wheels.

But I'm guessing it would still be "reacting" to a typical winter slip condition in the front wheels. eg. you're driving but hit a patch of ice. Unless this is an intelligent car, and even so, there would be no way for the car to determine when to engage the rear-wheels. It would have to 'react' to the slip. Especially if the conditions which enables it to 'predict' are not there (change in steering angle, throttle, ....).

 

In this respect, the "full time AWD" if I can call it that, would be a better system.

The Haldex system reacts in 1/7th of a wheel spin. (lookup 'Haldex' on wikipedia ). 1/7th of a wheel spin amounts to about 10 - 14 inches of travel when the wheel has traction. That amount of travel would take a fraction of a second, hence the reaction time might not even be perceived when you loose traction at speed. The system in the Ford Fusion is no slower than the Haldex and may even be quicker ...and it feels seamless. If, as you say a full time AWD system would be better, I can't imagine it being any more than minutely so... and likely not even perceptible.

Open diffs with traction control. TC will apply the brakes to one of the front wheels if it's slipping to send traction to the other wheel and cuts engine torque if necessary to maintain traction.

 

The WRX locking diff is in the center - locks torque distribution front and rear. The Ford system will anticipate the need for rear wheel torque and engage the rear wheels before slip is detected using the steering angle and throttle position (accelerating around a corner e.g.).

My experience driving an AWD Fusion on snow packed/icy roads is that all four wheels are getting torque. I often turn the traction control OFF and have a blast getting the Fusion going in easily controllable 4 wheel drifts around corners! Balance and predictability is perfect!