Automotive advertising will always rely on catchwords because it’s not practical to explain the mechanical specifics of a vehicle’s driveline in a 30-second ad. We’ve all heard the terms four-wheel drive, all-wheel drive, full-time and part-time. Are they all the same – meaning all wheels are driven or is there more to it? Read on to find out more.
Part-time four-wheel drive
Part-time 4WD is the simplest system, most commonly found system on older off-road vehicles like Jeeps, Land Cruisers and Land Rovers manufactured up to the early 1990s. Other part-time 4WD examples include utes and other light and heavy-duty vehicles. In a part-time 4WD, the engine sends its power to a transfer case which sends an equal amount of torque to the front and rear differentials and essentially ties their input shafts together.
What are the advantages of part-time four-wheel drives?
Part-time 4WDs are suited to slippery off-road situations as some torque is provided to both axles at all times.
What are the drawbacks of part-time four-wheel drives?
The drawback is that the vehicle can’t be driven in 4WD mode at all times. With the front and rear differentials rotating together, any difference in rotational speed between the front and rear wheels – e.g. turning a corner or uneven tyre wear – can lead to a drive shaft issue known as wind-up.
Full-time four-wheel drive or all-wheel drive
Full-time 4WD, also known as AWD or permanent 4WD, is a system that powers all four wheels at all times. It can be used full time on all surfaces, including dry pavement, due to the additional feature of a centre differential or equivalent device – e.g. Planetary gears etc.
What are the advantages of full-time four-wheel drives or AWDs?
The full-time 4WD’s main advantage over part-time 4WD is that it is always active. There is no way to get caught unprepared by a low traction situation.
What are the drawbacks of full-time four-wheel drives or AWDs?
Certain full-time 4WD systems may have drawbacks. The system can only deliver as much torque to one axle as is given to the other, due to the way differentials work. For example, if the front wheels are slipping, the rear axle will only receive as much torque as the front, and therefore the vehicle will not be able to gain traction.
Are four-wheel drive and all-wheel drive vehicles worth the higher price tag?
AWD or 4WD models generally cost more than equivalent two-wheel-drive models. Many SUVs are offered in the same model grade but with the option of 2WD or A/4WD. In this case, the A/4WD is usually a minimum of $2000 more than the 2WD version. For example, the 2022 Toyota Kluger GX auto costs $47,650 before on-road costs, but this increases when you option AWD. Whether the extra outlay is worth it depends on how the vehicle is used and where it is being driven.
<h2>Noel’s Progress Road Pitstop – the 4WD experts
Do you want to know more about four-wheel drives and all-wheel drives? Chat to the team at Noel’s Progress Road Pitstop. With more than 30 years’ experiencein the industry, our technicians are here to assist with all your mechanical needs. Not only do we provide servicing and repairs, but we also stock a huge range of parts and products, including tyres, mag wheels, rims and more. Located in Wacol, our state-of-the-art workshop welcomes vehicles of all makes and models.