LAND Rover's Discovery is one of the best 4x4s on the road or off and if you buy carefully secondhand, you're unlikely to be disappointed.

The main rule - as it is with every car - is never to buy without full or very nearly full service history, and if any car doesn't have it - walk away with your money clutched firmly in your hand unless you're prepared to take a chance at a much reduced price.

There are loads of sellers - dealers and private - out there, who don't seem to value service history and try to charge full market price without it. I would move on to the next one every time.

Discoverys are expensive vehicles with a lot of gadgetry, and you need to be sure everything has been properly taken care of by previous owners.

As far as you can, check drivetrain and suspension for anything unusual, plus obviously, look for off-road damage underneath or a seriously used tow bar.

After 2014 there was just one engine available - until a new model came out in 2017 - a smooth 3 litre V6 twin turbo diesel with 251bhp that suited the big Land Rover perfectly.

It has quite enough power to haul the heavyweight around even when fully laden and helped it win Towcar of the Year three years running.

The zero to 60 miles an hour sprint takes a good 8.8 seconds, and very best economy should be 36 miles per gallon.

On the road, it is just about as refined and quiet as the Range Rover, which is available with virtually the same engine and four wheel drive transmission.

Comfort is excellent over all surfaces, only slightly compromised by bump-thump from the large alloy wheels and tyres occasionally - something from which most big 4x4's tend to suffer.

Off-road, in the Land Rover tradition, it's virtually unstoppable, with standard eight speed automatic gearbox, low ratio gears and differential locks helping to make light of the stickiest situations and the steepest hills over any kind of terrain.

Should you ever want to, it will even see you safely through 800mm (2 feet 8 inches) of water without faltering - and I once proved that unintentionally during serious floods near my home. With an optional snorkel fitted, the Discovery will keep going with water up to the windscreen.

Roadholding and handling are fair - again in the 4x4 tradition - with quite a lot of body roll, but there's plenty of grip even when pushed pretty hard.

The interior is pretty up market as you would expect woith a premium 4x4, with soft materials and well - shaped, comfortable seats. All come with seven seats as standard.

Most bought secondhand will have had numerous options fitted from new, one of which is an excellent 360 degree camera system so that you can see all aroundfromthe driver's seat.

All have day running lights and stop/start and equipment is good even in lower order models like the SE, which comes with alloys, heated mirrors, an alarm, loads of airbags and other built-in electronic safety and traction control.

It also has parking sensors, audio remote control, headlight washers, cruise and climate control, and many will also have extras like leather upholstery and sat nav.

Pay about £19,500 for a '15 15-reg 3.0SDV6 SE, or £28,500 for a '17 17-reg SDV6 Graphite.