The cost of the technology is reducing the gap with 2WD as its use becomes more widespread.
For farmers and agri-business owners, 4WD (4x4) remains the core option. As you know 4WD systems sends power to each wheel and can provide enormous traction over terribly difficult underfoot off-road conditions. Over tarmac or easy terrain it isn't on all the time, with usually the rear wheels doing the driving.
All-Wheel-Drive (AWD) is on all the time - and primed to switch more power to whatever wheels need it in an instant. It usually gives most power to one axle when being driven on the road but the system automatically adapts to changes in milliseconds without driver intervention.
These vehicles are not designed to crawl over a field of boulders or over a muddy field. That remains the preserve of the 4x4.
We've driven some 4x4s up mountainsides, across muddy rivers and on hard rocky outcrops and have never ceased to be amazed at what a big torquey diesel engine and a good 4x4 system can do. Sometimes it looks like the impossible.
But AWD is now becoming hugely popular for on-road driving security - in SUVs, crossovers, saloons and estates - be it on a slippery road, an icy patch or towing a trailer with feedstuff or animals on board. The great thing about it is that it is all done for you. There is no need to switch it on or off.
Which is one of the big attractions and a help in explaining why the likes of BMW are fitting it (they call it xDrive) to their 3-series saloon for example.
Audi can boast quattro (all-wheel-drive) for some time and helped pioneer acceptance of it across mainstream motoring.
As far as farm families and rural businesses are concerned 4WD has always been part and parcel of their working lives.
Now many are looking at 4WD for the hard slog on the around-farm workhorse with AWD a real option on the family car or Crossover.
But there is a price to pay. Both 4x4 and AWD cost more than your conventional vehicle - though by no means as much as you might expect.
And they do tend to push up fuel consumption. That is the balance you have to strike between the reassurance and the price of the facility.
Against that backdrop of increased popularity across both modes, we have undertaken a survey of manufacturers and models now on the market to provide you with a guide to what is out there - and what is planned.