AWD usually means that the car will not engage another wheel until it detects slip. 4WD usually means all four wheels dig at the same time regardless.

 

R U sure?
Because the previous vehicle I just came out of (04 Grand Cherokee) was a 4X4 with Quadra TracII
Basically, the rear axle (rear wheels) was driving unless skip was detected then up to 50% of the power can be transferred to the front wheels.
That was when I was in Hi range
in 4WD Lo, all four wheels were digging....Basically for off road

 

Yeah, that jives with what I was saying. In the High range, you were AWD, in Low, you were 4WD.

 

Gotcha....
Makes sense now

So is it safe to say my front wheels will only engage if they detect a slip from the rear wheels?
In a way, it Kind of defeats the purpose of traction control.
My jeep never had traction control I guess because it had Quadra trac II. So there really was no need for traction control...

 

The 300 AWD is basically the older Mercedes' 4Matic system. 62% of the engine’s torque goes to the rear wheels and 38% to the front, fixed, at all times. That way it keeps the rear drive handling feel. It's not considered very sophisticated, compared to Audi or Subaru set ups, but it's effective nonetheless. AWD is AWD: Floor the throttle in wet conditions and you get no wheel spin, just instant forward thrust. Stay into the throttle on turns way past sane speeds and the car simply hooks up. 2009 and up AWD models feature a front axle disconnect system that only spins the front axle when AWD is needed.

 

Correct. The AWD system on our cars is always on system, exactly as described above

 

so if the disconnect fails, then the front wheels will have more "drive " all the time? we have a noise that ramps up consistent with wheel speed. it sounds like the wheels are driving an hydraulic pump.