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Originally Posted by BlackPearl Can you please let me know the following things about Compass and Tiguan -
1. Engine layout is transverse or longitudinal in each of these vehicles
2. Primary drive goes to front wheels or rear wheels |
Before we get into any contretemps, let’s look at the difference between an AWD and a 4WD:
All-Wheel Drive (AWD): A drivetrain that employs a front, rear and center differential to provide power to all four wheels of a vehicle.
Four-Wheel Drive (4WD): A drivetrain that employs two differentials and a transfer case to provide power to all four wheels of a vehicle. 4WD can be further split into full-time 4WD & part time 4WD
Full Time 4WD: Full-time 4WD operates as the name suggests. At all times torque is supplied to all four wheels, all of the time. The driver usually has several options available to them which affect the operation of the drivetrain depending on the conditions that are encountered.
In normal operation (such as driving on a bitumen surface) the front and rear axles are split by a differential which allows them to operate at different speeds when required — for example, when cornering etc.
In most vehicles there will be the option of ‘diff lock’. This locks up the centre differential and restricts any rotational difference between the front and rear axles. It’s a feature that is commonly used when off-roading to gain maximum traction.
There may also be the option of ‘low range’. Usually used in extreme off-road conditions and on steep inclines, this changes the gearing of the drivetrain to provide a torque multiplying effect.
Part Time 4WD: This is the original 4WD and the most basic one. Part-time 4WD vehicles tend not to have differentials between the front and rear axles. This limits the use of 4WD to off-road use because use of this feature on bitumen surfaces (where tyres have good traction) can cause excess stress and damage to the drivetrain (often called wind-up).
All Wheel Drive (AWD): All-wheel drive is in some ways similar to the full-time 4WD system, that also sends torque to all four wheels constantly. However, most modern AWD systems don’t offer drivers the option to operate in two-wheel drive and, unlike the 4WD systems, the differential between the front and rear axles cannot be locked. The differentials do, however, have ability to limit slippage between the axles if a low traction situation is encountered.
In AWD, this system works to get power to the wheels with the most traction by splitting torque between the front and rear axles on the center differential, and to the individual wheels by way of the front and rear differentials.
AWD isn’t quite as robust as 4WD and it can’t match the acute power delivery necessary for low-speed off-roading (i.e. rock crawling etc.). AWD systems simply cannot satisfy high-torque demands when the vehicle is off-road, therefore AWD vehicles tend to be more ‘car-like’ or ‘crossover’ wagon style than obvious off-roaders.
In most of the modern cars, computers are involved in most AWD systems. Sensors on each wheel monitor traction, wheel speed, and several other data points hundreds of times a second. An ECU (engine control unit) dictates where power is sent and to which individual wheel depending on whichever has the most grip.
Some AWD systems are essentially only part-time, driving only the front wheels until traction loss is sensed and torque is automatically directed to the rear wheels – eg. Honda CRV etc.
VW Tiguan uses the electronically controlled 4MOTION (AWD) system, where in, In normal driving conditions, power is supplied to the front wheels. This improves fuel economy versus running power through all four wheels all the time. However, when in need, the off-road drive mode offers all-terrain capability at the push of a button. This instantly switches on a group of advanced off-road technologies which work together to give you safer control over rough ground.
Compass sold in the international market, available in four distinct trim levels: the base
Sport, the mid-level
Latitude, the luxurious
Limited, and the off road-capable
Trailhawk. All trim levels are available with either front-wheel drive or four-wheel drive, with the exception of the Trailhawk trim, which will only be available in a 4WD configuration.
The reason I uploaded the below image in my previous post was to show the “4WD Low” & “4WD Lock” controls which can only be found in 4WD cars.
Source: https://www.digitaltrends.com/cars/w...l-wheel-drive/ http://www.motoring.com.au/what-is-t...-and-awd-7530/ https://en.wikipedia.org/wiki/Jeep_Compass