When is a 4×4 not a 4×4?

Car buying advice Car Technology
SsangYong Tivoli SUV 4x4 4WD badge

In these times of Tesco car parks being as full of SUV-style cars as the car park at Eton at the start of term, the 4×4 is not quite as it seems. After years of Land Rovers and Range Rovers being the preserve of the country elite, they began appearing in a less muddy format more and more often.

With most off-road vehicles never going off-road at all, manufacturers quickly realised they didn’t need to include full-time four-wheel-drive (shortened to either 4WD or 4×4) systems in their SUV models – in fact, quite often they didn’t need to include any kind of 4WD system at all. So the answer to the slightly odd title question is ‘most of the time’.

Today, many of the chunky-looking SUVs on the market are actually “faux-by-fours” with zero off-roading credentials whatsoever. Others have varying levels of mud-plugging ability, and only a few few are genuinely capable of going a long way from the safety of a nice piece of Tarmac.

Car manufacturers being what they are, there are dozens of different acronyms and terminologies used to describe a car’s drive system and, as usual, this is of no benefit to the customer but simply makes the marketing department look clever. So let’s look at the different systems and explain what it all means.

Traditional 4×4

Toyota LandCruiser 4x4 SUV off-road

There’s not many places on Earth that a Toyota LandCruiser 4×4 can’t get to.

Before we had a hundred different shapes and sizes of SUV and compact SUV – we had just a handful of ‘real’ four-wheel drive cars available in the UK. These included the iconic Land Rover and Range Rover, as well as some very capable Japanese offerings like the Toyota Land Cruiser and Hilux, the Mitsubishi Shogun, and even small Suzuki models like the Jimny and its predecessors. All of these vehicles had one thing in common; they all had traditional 4×4 systems.

When we talk about traditional 4×4 or 4WD, we are generally referring to a system where the front and wheels are getting an equal share of the drive at all times. So the engine is providing each axle with 50% of the overall drive it generates. This is different to your regular car, which only has drive going to one axle (either the front or the rear wheels, depending on the car).

Most vehicles using this sort of 4WD system also have mechanisms to lock the differential(s) in such a way to make sure left and right wheels are also getting equal drive. This last bit is critical because a normal car will always push the power to the wheel with least resistance. Anyone who has ever got a car stuck will have seen this, as one wheel spins furious while the the car goes nowhere. A locking diff system will mean that power goes equally to the right wheels, and this is what gets you out of the mud or snow.

Some models allow either the front or rear wheels to be disengaged, turning the vehicle back into a two-wheel-drive model when conditions did not require the extra traction, such as on-road driving. This improved fuel economy and wear on components, especially at the higher speeds achieved on Tarmac compared to gravel or mud.

Most traditional 4×4 systems also have a separate control level for high and low ratios. In normal use, the vehicle would be in high ratio, and in low-speed off-road situations the driver can switch to low ratio for improved take-off in low-grip conditions. This is a level of off-roading far beyond what most modern SUVs will ever need.

Four-wheel-drive vs. all-wheel-drive

In the 1980s, car manufacturers started exploring the idea of using four-wheel-drive systems for on-road performance rather than simply off-road utility. This came about as performance cars became ever faster and harder to control, especially in slippery conditions.

Two of the big drivers of this development were Audi and Porsche, who started using the term all-wheel-drive (AWD) to describe what was basically a 4WD system optimised for on-road use. The other major difference was that these vehicles used systems to vary the amount of drive going to the front and rear wheels, rather than a simple fixed 50:50 split.

Porsche 959 prototype

Clearly this Porsche 959 would never be any good off-road, despite having all-wheel-drive. That would be just silly, right?

With over 30 years of development, many of these systems have become highly advanced, and can control the amount of drive going to each wheel to ensure best overall grip and performance. There are a variety of systems used to achieve this by different manufacturers, but the principle remains the same.

In principle, four-wheel-drive (4WD) and all-wheel-drive (AWD) are the same thing – assuming you have a vehicle with four wheels! However, 4WD is generally used to describe an off-road vehicle while AWD is usually applied to on-road applications. Manufacturers, typically, have ignored common sense and applied their own terminology to these systems: Audi kicked things off with the name quattro, but these days BMW calls its AWD models XDrive, Volkswagen used to use Syncro but now uses 4motion, Mercedes-Benz uses the name 4Matic, and so on. The principle is the same; a variable all-wheel-drive system which is largely designed for on-road use, although it may well be very competent in a number of fairly gentle off-road scenarios.

Two-wheel-drive SUVs

This group of vehicles is the answer to the question posed by the title to this article. Not every butch-looking SUV has genuine off-roading hardware underneath the flared wheelarches and side steps. In fact, these cars may be no better than a common hatchback or saloon when the going gets muddy or snowy, and the genre has been been dubbed “faux-by-four” by critics.

Car companies worked out that customers loved the look of big four-wheel-drive vehicles, but rarely do the majority of these cars go anywhere off the beaten track. In fact, they are mostly used for popping down to Tesco or Waitrose (depending on how you view your place in the social hierarchy) and dropping the kids at school. In other words, normal car stuff. So, reasoned the manufacturers, there was absolutely no need to burden their vehicles down with heavy and expensive 4WD running gear. Take out half the drivetrain and you get a vehicle which has better performance, better economy, lower emissions, lower servicing costs, is much cheaper to build and – importantly – still has the all-important ‘lifestyle’ appeal for buyers. As long as they don’t want to actually act out those lifestyle feelings by getting their car muddy.

Honda HR-V faux-by-four

Crossover, soft-roader, whatever. It’s basically a hatchback on steroids.

What has been most pleasing to manufacturers, however, is that the remarkable appetite from buyers for these vehicles has allowed them to charge hefty premiums for all sorts of soft-roaders, crossovers and other marketing buzzwords which describe cars that look like trucks but are not. Basically, Volkswagen can butch up the looks of the Golf, stick a Tiguan badge on it and charge a huge premium for the privilege. The Honda HR-V is little more than a Jazz on steroids, the BMW X1 is a 1-Series hatch on stilts, the Nissan Juke evolved from the Note hatchback platform, and so on. Some of these are available with a four-wheel-drive option, but by default they are simply two-wheel-drivers with added height and weight. If you are wondering what sort of drive system your chosen chariot may have, check out our new car comparison tool to get a detailed breakdown of the technical specifications for all SUVs currently available in the UK.

For a huge number of drivers, a 2WD SUV is the perfect option, as they never intend to drive off-road anyway. As long as they appreciate that their car will be no better (and often worse) than a run-of-the-mill hatchback when it starts snowing, since these vehicles generally offer nothing in the way of extra traction or off-road capability.

Servicing and running costs

As with all cars, SUVs need servicing and looking after. It will probably come as no surprise that four-wheel-drive and all-wheel-drive cars might need some extra attention, due to the extra wear and tear created by having twice as many driving wheels and associated assemblies.

If your car is a 2WD SUV, your servicing and running costs should not be very different to a regular hatchback or saloon, so make sure you are not being ripped off by the dealer or garage just because your car is an SUV.

Whatever type of SUV you drive or choose to buy in the future it is important to understand what it is capable of. It is also important not to be lured into buying a large heavy two wheel drive car under the false impression it might be useful if it starts snowing… it may not be.

Porsche 959 winning the Dakar rally

No good off-road, they said… A slightly modified Porsche 959 en route to winning the Paris-Dakar Rally in 1986

Article provided by Mike James, an independent content writer working together with AA Motoriety and Ade Holder of Holder Motoring.

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