AWD vs 4WD vs FWD vs RWD

FWD-vs-AWD-Blog-Feature

AWD vs 4WD vs FWD vs RWD – SUV BUYER’S GUIDE

In the good old days, you could tell a lot about a car from either the sales brochure or even the badges on the boot of the car itself.

These days? Not so much. Three-letter acronyms (TLAs) like AWD are not only rampant, with the potential for huge confusion, but they can also be misleading.

What, for instance, is the difference between front-wheel drive and rear-wheel drive? And how is all-wheel drive different to four-wheel drive? And what does it mean to the family that owns the SUV in question?

FWD vs RWD

So let’s start with the easy stuff: Front- or rear-wheel-drive. As the name suggests, this is a description of which wheels provide the actual propulsion for your car.

These days, even in the world of SUVs, front-wheel drive is very common. It’s a more compact layout that takes up less of the available space, meaning more room for a growing family.

Rear-wheel-drive, meanwhile, is the old-school approach to laying out a vehicle and, in modern SUVs, it’s rarely seen at all. Either way, if your SUV is a rear-wheel or front-wheel drive, it’s also a two-wheel-drive. That is, only two of the four wheels are ever providing the power that gets you down the road.

AWD vs 4WD

The bottom line here is that there’s four-wheel drive and all-wheel-drive and, in the context of modern family SUV terms, they mean much the same thing.

The confusion all goes back to a previous point in marketing history when SUVs started to emerge from the primordial swamp as off-road vehicles, and then began to shed some of the weight and complexity that many buyers didn’t need.

It seems that while a lot of families wanted a vehicle that had a high ride-height, tough looks and appeared as though it could scale Uluru, actually driving it off road was never on their radar.

And so the SUV was born. This was also the point at which the whole AWD vs 4WD thing was high jacked by the marketing departments of the world.

Back when the SUV was still emerging, a ‘4WD’ badge indicated that a vehicle could drive all its wheels at once to maximise its ability to jump over rocks and churn through bog-holes. Some of these vehicles could run in rear-wheel drive on the road and then be switched to four-wheel drive for the rough stuff. Others ran in four-wheel-drive all the time. But this is old technology and now restricted to off-roaders, not family SUVs.

All-wheel drive, meantime, was a term used to describe a car that also drove all four wheels but did so as a means of maximising traction and grip (and therefore safety) in an on-road scenario. Things like Audi Quattros and Subaru WRXs were great examples. They were terrific in the snow or on wet or gravel roads, but they were definitely not off-roaders. But in a purely technical sense they were four-wheel drive.

But as the world shifts towards a motoring future dominated by the SUV, the term ‘four-wheel drive’ is starting to disappear, with ‘all-wheel drive’ taking over. Again, simple this is not, because there are two distinct types of all-wheel drive, both of which (technically) allow the maker to apply an ‘AWD’ (or even ‘4WD’) badge to the tailgate.

 

Full-Time AWD

The first – and technically superior – type of all-wheel drive works in a similar way to those Audi Quattros and Subaru WRXs in that it drives all four wheels all of the time. This gives much more grip than a two-wheel-drive system, although it does add weight and complexity that will show up in servicing and fuel costs.

 

Part-Time AWD

The second type of all-wheel drive is a simpler, cheaper, arguably less effective system that makes the SUV behave as a two-wheel-drive (usually front-drive) vehicle for the majority of the time.

Only once the computer has detected wheel-slip (a skidding tyre) will it send some power to the other (usually rear) wheels. The system is reactive and while it can often salvage a situation, it can’t do anything until the loss of traction has already happened. Then again, modern electronics are so sharp that the car will often save you before you know you have a problem.

While the SUV is driving along normally in front-wheel drive, it will use less fuel than the equivalent SUV with the other type of all-wheel drive.

The thing is, you can’t tell which type of system you’re buying just by looking at the badge or by asking the seller A dig into the specification sheet is required. A chat with the dealership’s service manager is an even better idea.

And even with the simplest of AWD systems, you’re still carrying around the weight and complexity of the extra driveshafts and differential even though you mightn’t use them in a full 12 months of driving.

The other potential downside is that some car makers will insist you can only have the AWD badge if you pay for the upmarket model, or the one with the bigger (thirstier) engine. Or both.

So, do you need AWD in an SUV? For most people, the answer is probably no. If you do regular trips to the snow, live up a rutted farm track or launch a tinny from greasy boat-ramps, then maybe all-wheel drive is worth the extra money. Even then, the simpler version of AWD is probably enough to keep you out of strife. But for the rest of us, front-wheel drive in an SUV will do the job and save money.

Pros/Cons FWD vs RWD vs 4WD/AWD

Here’s how it pans out in simple terms:

ITEM FWD RWD 4WD/AWD
Means: Front-wheel drive. Only the front wheels are ever driven Rear-wheel drive. Just like FWD but only the rear wheels are driven Four-wheel drive/All-wheel drive. All four wheels are driven constantly or due to wheel-slip
Pros: Simple; cheaper to buy and maintain; maximises interior space Mechanically simple; better for towing Superior grip and safety particularly on slippery surfaces; best of all for towing
Cons: Will run out of grip first Drive line eats into interior space; rare to see now More expensive to buy / run / service. Can increase fuel consumption

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Jez Spinks

Automotive Journalist