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Toyota Prado - 4WD Systems |
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4wd systems - basicLast Updated: 09 May 2008 First of I want to say that I'm not an expert at 4wd systems. But I will try to describe simply what I have observed various how various 4wds systems work in off road conditions and in reference to the Prado's system. The Prado has permanent All Wheel Drive (AWD). This means that all 4 wheels should be providing some sort of drive when moving on normal roads. Usually if one of the rear wheels loses traction its opposite wheel doesn't receive and power either. However the Prado has a LSD at the rear so that means this doesn't happen. If one of the rear wheels has traction the other side will have some sort of power. The front wheels of the Prado in some specs. eg GX and GXL do not have front LSDs so can suffer loss of power if there is no traction. As with the left to right - the system works the same way from front to back of vice versa. However the Prado has a lock center diff so this doesn't happen. - I think... All Prado's have a central lockable differential in addition to being a TORSEN type it has LSD capability). This is the key in allowing AWD on hard surfaces, eg. normal roads. This diff allows power to be transferred to the front or back. Notes: AWD cannot be turned off. This type of standard system has been in use for many years and is a step up from more basic systems. Eg. those found in most Subaru's bar the performance models. I hope I got it right...?
What is DAT ? Well it stands for 'Driver Assist Technology' and is used by Toyota to describe a number of 4wd technologies. DAT is a specific to Toyota, however its concept is the same as other manufacturers who have their own system names. It main components are a stability control system (VSC) traction control (TRC), downhill speed control (DAC), hill start control (HAC) and arguably adjustable height rear air suspension (TEMS). () represent Toyota's acronyms. Only the Grande models have all the complete DAT systems. The VX comes close minus the TEMS feature. Now basically it all adds up to a pretty formidable off-road ability and made even better with the VSC system which you can turn off when by locking the center diff. So in sand especially the wheels are given maximum power. Land Rover, Ford, GM and all have some sort electronic systems to enhance their 4wd systems.
The Prado also has decent suspension travel and a rigid rear axle which although old tech increases 4wd ability. The only negative so far is size, Had to stop and move debris away so the paint work isn't scratched.
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Opinion and summary Based on what off-road tracks we have been on the GXL's system works very well indeed. Remember its not just the 4wd hardware but the gearing especially low range, extra height, suspension travel and engine power that makes it very good in various conditions. Don't forget driver ability and experience helps too ! I also find it ironic that the 'luxury-version' gets the most aids whilst the models that need them most - Ie. basic versions don't get them. Let's face it how often do you see a luxury 4wds on the beach or in the middle of nowhere. I haven't and I go everywhere ! All current Prado's have independent front double wishbones in the front with gas dampers and coil springs and live axle rear also with gas shocks and coils. Only the Grande aka top range model version gets pneumatic or 'air bags' instead of springs. One last thing. If a road you're traveling on is slippery and no wheels have any traction it doesn't matter whether it is 4wd, AWD or whatever you won't be going anywhere in a controllable fashion.
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