4WD vs AWD

What is the difference between 4WD & AWD Vehicles? Over the years, the lines have blurred for consumers in terms of what is understood by off-road capability. We now see a wide range of technologies and variants in vehicles to the point that most people don’t really know how to determine the difference between AWD and 4WD and how and when it matters. To confound the issue even further are the terms SUV and Softroader. To help you better understand this grey-line of vehicle suitability here’s a breakdown of terms and definitions followed by a list of popular vehicles available in Australia divided into their respective AWD and 4WD categories.
Article By: ExplorOz Team
Created: February 2016
Revised: March 2016
Latest Feedback: April 2016

What is Four Wheel Drive (4WD)?

"4x4" in a vehicle means there are 4 wheels total and 4 wheels that are driven.
There are two types of 4WD systems found in the 4x4 vehicles in today’s market – either Part-Time 4WD or Full-Time/Constant 4WD. Both are ideal and meant for off-roading.

Virtually all of the 4x4's sold in the early days were based around a Part-Time system with some still in use today, although the Full-Time /Constant 4WD has become prolific (but more about that later).

PART-TIME 4WD

The rear wheels of the 4x4 are driven by a conventional transmission and differential and operated in exactly the same fashion as a two-wheel drive car. The driver selects four wheel drive only when required by engaging a transfer case. In older models of 4x4 this was done with a second gear lever and turning locking hubs on the front wheels (ie. stopping and getting out of the vehicle). However, now this is usually done by pressing a button on the dash and the hubs will lock automatically. Whilst modern part-time 4WD’s come equipped with many extras the principle remains the same - the vehicle operates in 2WD (part-time) until a transfer case engages the front wheels and delivers power 50/50 between the front and rear diffs. A part-time system (in 4WD) does not allow front and rear wheels to act independently - the front and rear sections are driven at the same rate.

The transfer case will also have the option to switch into a lower gear ratio to provide extra torque when tackling extreme terrain. Changing from High to Low Range is done with the second gear lever (in older models), or by pressing a button (with newer models). There are 3 modes of operation - High Range 2WD, High Range 4WD and Low Range 4WD.

Having less moving parts in the front of the vehicle is an advantage of the part-time system and aids in conserving fuel usage.

Part time four wheel drives can only be driven on a bitumen surface in conventional mode (two wheel drive). Driving with 4WD engaged, on hard, smooth surfaces generates 'transmission wind-up' and can cause severe drive train damage.

FULL-TIME (CONSTANT) 4WD

The Full-Time 4WD has a centre slip diff allowing each wheel 25% of the available torque. The centre differential allows 'slippage' between front and rear drives while the diffs at either end cater for slippage between their respective wheels. The driver of the vehicle can lock the centre diff (by button or lever) to ensure torque is delivered equally to both ends of the vehicle. When the centre diff is locked, you must be conscious not to get transmission wind-up, so just as with the part-time 4WD, the vehicle cannot be driven on hard, smooth surfaces such as the highway in this mode.

The Full-Time 4WD system is equipped with low-range gearing for added off-road ability. There are 3 modes of operation: High Range 4WD, 4WD “Locked” High, and 4WD Locked Low. There is no 2WD mode.

With this type of system the vehicle and driver will benefit from the AWD feature on the road and the 4WD feature when off-roading, so can be considered the best of both worlds.

4x4 vehicles (whether constant 4WD or part-time 4WD) are deliberately constructed for the purpose of driving in off-road terrain so they are also equipped with large profile tyres and rims, have low range gearing, have high ground clearance with superior approach, departure and break over angles. They would also typically be large vehicles with a large load and towing capacity.

These vehicles are therefore ideal for those drivers who need to tow a large caravan, boat, or trailer, and for drivers you want to negotiate difficult off-road terrain when more torque and/or slower speed is needed.

Importantly for Australian touring, if you wish to have a vehicle that you can take over sand dunes (either beach or dessert) or through natural bush terrain such as hilly unmaintained tracks where erosion causes washouts and track rutting, and to negotiate rocky sections where wheel travel and angles become critical factors, then you will require a 4x4 (and it doesn’t much matter if it’s full-time or part-time).

HIGH/LOW RANGE

To enable a 4WD to travel at lower speeds while travelling on rough terrain it needs lower gear ratios. Not all 4WD’s have low range gearing and this restricts their ability to tackle rough terrain. However 4WD’s that lack low range gearing are generally not built for severe off-road conditions.

What is All-Wheel Drive (AWD)?

All-Wheel Drive vehicles are designed to improve on-road drivability through the use of a system that powers all four wheels at all time (like a 4WD) but 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. Usually this ability is provided with a differential known as a viscous coupling although more recently a similar outcome has been achieved by using electronically-controlled hydraulic or electro-magnetic ‘clutch’ systems.

AWD requires no driver action to implement driving power to all four wheels. The difference to a 4WD is that a 4-Low setting is not available. Due to the lack of a “low range”, AWD vehicles are much less capable in off-road terrain but have advanced on-road traction control to handle muddy, wet, ice slippery conditions. In fact, AWD vehicles are better equipped to handle on-road conditions than a 4WD, such as a sudden slippery corner or sudden heavy breaking as there is twice the available traction.

Some AWDs are styled as cars and are more obviously designed for city or sporty driving. Other AWDs however are styled and promoted as SUVs however this in itself does not indicate that the vehicle is suitable for taking offroad. Buyer demand has created the SUV market where a higher seating position, and high-tech features deliver exceptional performance and safety through the AWD system and these vehicles might look like a luxury 4WD but are not.

SOFTROADERS

Most AWD’s are termed “Softroaders as they lack the credentials to tackle truly offroad conditions.

At road speeds of anything about 30kph or above on a smooth surface AWD works well. However at lower speeds it handles poorly on uneven terrain, soft sand, mud, rough hill climbs/descents etc.
The ground clearance of AWDs varies, but generally range between 165-220mm. The higher the ground clearance the greater capability to negotiate uneven and rough road conditions, as the vehicle has a lessened chance of sticking or the underside being damaged.

“Softroaders” do not meet the 220mm ground clearance minimum that is required for offroad driving. The lack of sufficient ground clearance is an important factor in being capable of venturing off formed dirt roads and tracks. Whilst they might manage the dirt roads such as those found in National Parks and regional areas, they are not equipped for fire-trails, State Forests, or long-haul tracks, desert expeditions, or soft sand dunes on the beach or deserts.

Other factors such as lightly built suspension components and little underbody protection would also limit the use of a Softroader in offroad conditions.

In addition if going offroad you should always carry a spare tyre/wheel that match the 4 rolling ones. Many AWDs including the luxury models such as Volvos, BMWs and Mercedes-Benz don’t have proper spares.

Tyres are yet another important consideration. Soft-roaders leave the factory on tyres that aren’t suitable for the bush where the heavier built casings of Light Truck tyres found of 4x4s make them more resistant to punctures.

Another problem the newer AWD's have is automatic CPU traction and brake assist. When driving on sand the traction assist will force spinning wheels (even if a slight spin) to jar on and off, much like the ABS when braking hard. When the Awd system creates this jarring effect on the wheels, it actually causes the vehicle to get bogged, in other words the Awd system will dig for traction, not a good idea on the sand.

Availability of parts, tyres and spares is a major concern when taking passenger vehicles into remote areas of Australia and is one of the reasons that many 4WDrivers stick with the traditional truck body style of 4WD.

Pushing softroaders into many typical Australian pursuits stresses them beyond their design limits and results in mechanical trouble and heartache for the owners.

AWD Makes & Models

TOYOTA - Kluger, RAV4
NISSAN - X-Trailer, Dualis, Juke
RANGE ROVER - Evoque
MITZUBISHI - ASX, Outlander
FORD - Territory, Kuga, Escape
HOLDEN - Captiva
SUBARU - Outback, Forester
SUZUKI - SX4, Kizashi
MAZDA - Tribute
HYUNDAI - Santa Fe, ix35, Tucson
HONDA - CR-V
DAIHATSU - Terios, ROCKY/FEROZA/F-300 OR F-310
KIA - Sportage, Sorrento
RENAULT - Koleos
SKODA - Yeti
PEUGEOT - 4008
SSANGYONG - Korando, Rexton
VOLKSWAGON - Tiguan, Amarok
VOLVO - XC60
MERCEDES BENZ - GLA
LEXUS - RX, NX
BMW - X5, X3
AUDI - Q7, Q5

4WD Makes & Models

TOYOTA - Landcruiser, Prado, FJ Cruiser, Hilux, Fortuner, RAV4
LAND ROVER - Discovery, Defender, Freelander, Range Rover
JEEP - Cherokee, Wrangler, Commander
ISUZU - D-Max, MU-X plus Trucks - NPS, FTS800, NLS
MITSUBISHI - Pajero, Triton, Challenger
NISSAN - Patrol, Navara, X-Trail, Pathfinder
FORD - Ranger, Everest, Territory, Escape
MAZDA - BT-50
HOLDEN - Colorado, Jackaroo
SUZUKI - Grand Vitara, Jimmy, Sierra
DAIHATSU - Rocky, Feroza, F-300, F310
LEXUS - LX470, LX570
MERCEDES BENZ - G & GL Class, M & ML Class plus Trucks - Sprinter, Unimog & Zetros
VOLKSWAGON - Touareg
RENAULT - Koleos
SSANGYONG - Rexton, Korando SX
PORSCHE - Cayenne
FUSO - Canter 4x4 (truck)
AVIA - D120 4x4 (truck)
IVECO - Daily 4WD (truck)
Mahindra - Genio (truck)

4WD & AWD Forums

You can speak to owners of 4WDs and AWDs of all makes/models on the ExplorOz Forum. Our Forum has over 74,000 registered users, the majority of whom are Australian's and many vehicles makes/models are represented by the Membership.

Our Forum is an active community of like-minded people where you can ask questions related to your vehicle, trip planning or on-the-road logistics or just share stories, ideas, get opinions. There is a strong community spirit on ExplorOz with site users enjoying the live, vibrant discussions in the Forum and many joining up for trips away together, coordinated in the Members Trips & Gatherings section.

Whether you are looking to discuss problems with a particular make/model of vehicle, or looking for advice on what to buy then you can find the answer in our Forum. If you can't find the answer you're looking for, just create a new thread.

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Article Tags

4Wd Forum, Awd Forum, Toyota Landcruiser, Prado, Fj Cruiser, Rav4, Hilux, Fortuner, Nissan Patrol, Navara, X-Trail, Pathfinder, Land Rover Discovery, Defender, Freelander, Range Rover, Range Rover Sport, Mitzubishi Pajero, Triton, Suv, Softroader, Awd, 4Wd, Four Wheel Drive, Problems

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