cheers guys , know it's a very complicated subject and agree that different companies use different classifications of there motors
ref the all wheel drive is the viscious then also designed to prevent wind up ,
it does seem the newer styled landies have superior traction than the older landies
regarding the traction control i assume they are better off road than using diff locks , due to it being able to send power to the wheel that has traction , as i always thought even with a diff lock engaged if one wheel on each axle looses grips it won't go anywhere
where's the traction control is an improved class in being able to offer better grip off road
but in saying that the merc g wagon has 3 x diff locks as is supposed to be virtually unstoppable off road
then read reports of traction control and diff locks shouldn't be used at the same time
it seems the land rovers knock spots off other four wheel drive vehicles , had a mate who bought a bmw x5 and was useless even on grass ,
like to know what makes the landies so good and being a boring old git in what makes them so superior than other 4x4s
A basic understanding of diffs and 4wd setups would help wonders here. Loads to find via Google and YouTube.
If you take a traditional 90/110, they have open axle diffs and an open, but locakable centre diff. With the centre diff locked, they will perform the same as a Series or most Jap trucks that only have 2wd and 4wd modes.
With the centre diff locked, both output shafts (front and rear props) will rotate at the same speed. And cannot move independently. 100% torque will be being sent in both directions. Torque and Power are not the same thing.
At the axle, the axle diff will also split the torque sending 100% to each wheel.
The important bit here is, you will not see power without resistance. e.g. if you have your Land Rover in neutral and not moving and you blip the throttle, it won't make hundred horse power. You need to apply load to the engine to see the Power. This is why dyno's, such as rolling roads need a way to load the engine.
If both wheels on the axle have traction, then both wheels will be loaded, so you see power at the wheels and the vehicle moves. If one wheel is lifted off the ground, then suddenly there is no loading, so, as torque is split 100% to each side, you suddenly see no power at the wheels. Which is why, even with one wheel on the ground, it doesn't rotate. The answer is simply there is no enough power making it to the wheel to make it turn and rotate.
Traction control will brake the wheel in the air, the spinning wheel. Thus provide loading. This will mean Power is also seen at that wheel and thusly the other wheel. The more loading, the more power.
Traction control works very well off road, but comes with some downsides. Firstly it needs a spinning wheel to work, so it is a 'reactive' traction aid. And requires the driver to keep on the throttle for the traction control to actually work (too many people lift or back of the throttle when trying to use TCS).
Prolonged use can also cause high brake wear and even over heated brakes. And in some situations it may still struggle to make the stationary wheel turn, as there is only so much loading that can be applied.
Advantages however are. Very easy to implement on cars that already have ABS. Can be turned on and off. Gives full steering control while in use and doesn't really affect turing circle. And on slippery conditions like ice, snow or wet grass. Can work well in keeping all the wheels spinning.
Full on locking diffs will essentially join the two wheels together. So when one turns, so will the other. The advantage here is, it is a proactive traction aid. i.e. you don't need to wait for slippage for it to activate.
Downsides are, often costly. Affects steering and reduces turning circle. Can require strong drivetrain components. Not suitable for passive use on high traction surfaces.
As a rule, spinning all the wheels equally will help with traction. Although can get you very stuck in the progress. On mixed grip surfaces however, TCS can offer more appropriate grip where it's needed, rather than the sledge hammer result of lockers.
Going back to a 90/110. Getting cross axled is common. This is where diagonally opposite wheels are lifted in the air. Which means that no power is making it to any of the wheels.
Such a thing is common for 'most' off road 4x4 vehicles.
A 90/110 with TCS however will be able to drive out of a cross axle situation. Based on what I just explained above. So yes, latter Defenders, when equipped with TCS are more capable than older ones.
With the likes of the Freelander. They don't really operate all that differently. How the power makes it to each wheel is essentially the same. It just uses different types of couplings and as standard is FWD biased until the wheels slip. This is the coupling working, not electronics.
The TCS of a Freelander, or D3, RRS current new RR, etc. All work the same way as explained above. The biggest difference is, all of these vehicles use independent suspension and are much more prone to lifting wheels off the ground. So TCS is much more needed.
