guy

I think this will be a fun discussion and with lots of new members we can all learn and compare thoughts.<br>
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Let's first establish some definitions and then compare and contrast them...<br>
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Here is my view of things:<br>
First some definitions:<br>
<b> Open differential </b>- a differential that provides power to both sides, however the faster turning side will sap power/torque from slower spinning side<br>
<b> Locked differential </b>- a differential that always provides power to both sides most typcially 50% to each<br>
<b> limited slip </b>- typically a rear differential that sends torque/power to the slower turning wheel away from a spinning wheel, opposite an open differential. Slower wheel is one with traction.<br>
<b> posi traction </b>- typically a rear differential that begins to form a locked differential when one side spins faster than the other.<br>
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1. <b> 4 wheel drive (part-time)</b> - implies locked center differential, but open front and back differentials. Guanteed to power at least 2 wheels. Front or rear slippage will get all torque/power for that axle no-traction will be achieved.<br>
2. <b> 4 wheel drive (full-time)</b> - same as #1, but center differntial is 'open' not locked. Any 1 wheel on vehicle can sap all torque/power.<br>
3. <b> all wheel drive </b> - typcially a vehicle that controls the 3 differentials. Most often it utilizes clutches to create 3 closed differentials: center, front and rear. techniques can also vary torque to each side of the differentials.<br>
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<b> any others </b> other variants?<br>
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To me, it appears that the ML is an all wheel drive using 3 Open differnentials (high range) and utilizes ABS to prevent the sapping of torque/power to a slipping wheel.<br>
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Benefits of AWD is a more natural handling.<br>
Benefits of 3 locked differntials (locked 4wheel drive)is full power to all wheels with no delay.<br>
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I believe in Low Range the ML only locks the center differential.<br>
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I look forward to others thoughts and information - especially if I have made mistakes.<br>
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Personally, For snow driving I prefer Locked differentials as it provides even power and balance since 1 or more wheels will always be slipping due to locked differentials and varios traction/turning radius conditions.<br>
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I think AWD is better for all other conditions with the exception of maybe drag-strip acceloration unless differentials ensure power to all wheels when slippage occurs.<br>
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Guy