Jeep has a very long history in the manufacture of off-roaders starting way, way back in 1941 with the Willy’s MB. They were developed for use by the US Army, but it was just four years later that the Willy’s Jeep became the world’s first mass-produced four-wheel-drive car.

Fast-forward 78 years and the firm is still building rugged off-roaders that possess almost unrivalled off-road ability but it’s on the road where the modern Jeeps will have to prove their worth.

The Wrangler, reviewed here, is rightly revered for its all-terrain invincibility and its styling sends out a clear message about the kind of life it was built for. For the fourth generation model Jeep have largely just tinkered with the exterior and it retains some traditional and instantly recognisable styling cues such as the round headlights, the seven-slot grille, trapezoidal wheel arches and visible hinges.

There are three trim levels available: The Sahara, Europe-only Overland and the Rubicon, with its switchable front anti-roll bar, heavy-duty alternator, 32in Goodrich Mud-Terrain tyres, locking differentials and the ability to take a winch without requiring modification.

It’s unlikely anyone on these shores will ever need that level of hardware but beneath the subtly revised bodywork each version retains its reassuringly robust ladder-frame chassis, solid axles and two-speed transfer case. To improve fuel economy, the drivetrain can be switched to rear drive at speeds of up to 45mph.

Beneath the bonnet of my test car is Jeep’s new 2143cc turbocharged four-cylinder MultiJet-II diesel which is coupled with an eight-speed automatic gearbox. It produces 197bhp and 332lbft of torque from 2,000rpm.

Unlike the Rubicon, the Overland is fitted with hybrid off-road tyres, although both have full-time mechanical four-wheel-drive. Both versions also use rigid axles manufactured by US specialist Dana.

It rides on coil springs and passive dampers and, to protect the underside of the vehicle, there are four skid plates shielding the fuel tank, the transfer case and gearbox oil pan. In a further example of the Wrangler’s true purpose in life, the 242mm of ground clearance is among the best of any mass production vehicle while the approach, departure and breakover angles of 35.4, 30.7 and 20 degrees allow it to put greater distance between it and the run-on-the-mill SUVs that we’ve become accustomed to seeing on our streets.

The hardware that makes the Wrangler such a formidable off-roader does compromise its on-road manners but not as much as the previous model. The steering, at 3.3 turns lock to lock, can feel impossibly slow during low-speed manoeuvres while changing direction at higher speeds requires a significant amount of planning and effort.

The slower steering doesn’t, however, imbue the Wrangler with easy stability at higher speeds. It is, of course, vulnerable to being nudged off-course by strong winds thanks to its sheer bulk and boxy shape but even without the application of external forces you’ll find yourself having to often correct its line.

Through bends the Wrangler’s handling is precisely as you would expect: It is a big, heavy car that leans heavily on the outside wheels and there’s limited grip at the front leading to inevitable understeer if you attempt to hurry it along.

The thing is, Jeep are attempting the impossible. Or, at the very least, the improbable by necessarily retaining the architecture that makes the Wrangler such a formidable beast off-road while turning it into easily accessible, everyday family transport. The engineers deserve plaudits for the strides they have made because, despite its lack of handling finesse, the Wrangler manages to provide a reasonably comfortable and refined environment in which to travel.

The suspension dispatches larger holes and bumps in a respectably damped way and, while rebound is not so well controlled, the car doesn’t float too much over crests. Patchier surfaces keep the Wrangler’s chassis busy and, although that distant lumpiness is persistently nibbling away at occupants’ backsides it never becomes overwhelming.

It’s on asymmetrical stretches of road where random undulations that work one side of the axles more than the other that the ride really suffers and passengers will find themselves being tossed around, though it never becomes significant enough to induce motions sickness.

Efforts to shield occupants from engine, wind and tyre noise are hampered a little by the decision to make the Wrangler so easy to disassemble. The diesel engine is particularly audible when it’s being worked hard while on road and wind roar provide a persistent backing-track to any long-distance journey.

Because Jeep are trying to push the Wrangler more into the mainstream its performance on the road becomes as an important piece of the puzzle as off it.

The 2.2-litre MultiJet-II turbodiesel makes positive contributions to the Wrangler’s improvements in refinement and driveability. It’s coupled to a new eight-speed automatic gearbox that, while designed for tougher tests than even British roads can pose, is well-mannered and smooth.

It does have a tendency during normal driving to shift languidly into the highest available gear but keeping the engine in its 2,000 – 3,000 rpm sweet spot is easy enough using manual controls.

It will sprint to 60mph in a surprisingly sprightly nine seconds. The use of variable-geometry keeps turbo-lag at a minimum and, along with the engine’s fundamental smoothness, progress is more civil and car-like than expectations allow.

The cabin is a pleasant-enough place to spend your time. The leather seats are comfortable and supportive and the plastics feel tough and tactile. The controls are sensibly laid out and easy to use too.

Front seat passengers aren’t blessed with acres of space, something that might come as a surprise in a vehicle this size. The door apertures are relatively small and the sills high and, even when you’ve manoeuvred yourself into the high-set driver’s seat, you’ll discover marginally less legroom than you might expect.

The thing to remember, however, is that the Wrangler isn’t like any other SUV. Can you name another car in this class that allows you to fold the windscreen flat? Or remove any or all of the doors and the roof? There are, in fact, a number of options available to make open-air motoring in the Wrangler as easy as the press of a button.

Rear-seat passengers arguably fair better, with head and leg room that’s largely on a par with what you’d find elsewhere. The Wrangler will carry 533 litres of your luggage with the rear seats in place. Folded flat, that increases to 1,044 litres.

The Wrangler is fitted with the company’s fourth generation Uconnect infotainment system. It sports an 8.4in touchscreen mounted in the centre of the dashboard. Apple CarPlay and Android Auto is included but if that’s not your bag you can use the standard factory navigation. The home screen allows you to group together functions that you use most frequently.

The system isn’t particularly responsive. At times you’ll find yourself poking the screen two or three times before anything happens. Thankfully there’s a row of shortcut buttons beneath the screen that help make life a little less painful.

The latest Wrangler retains its reputation as one of the toughest, most capable off-roaders on the market, and its image reflects that. However, it’s the great strides that have been made in on-road driveability that impresses the most.

The cabin is more spacious and quality much-improved. It still doesn’t ride or handle with quite the same finesse and polish as many of its rivals but, when you consider what it can do when you’re separated from the nearest Tarmac by miles of almost impassable countryside, it isn’t hard to find a little forgiveness.

If you want an SUV with proper off-road credentials but can still serve as everyday family transport, it would be hard to find a better proposition than the Wrangler.

Jeep Wrangler Overland four-dour 2.2 Multijet II

Price: £48,365

As tested: £49,140

Engine: 4-cylinder turbocharged diesel

Transmission: 8-speed automatic

Max power: 200hp

Max torque: 450Nm @ 2,000rpm

Max speed: 112mph

0-62mph: 9.6sec

EC urban: 29.1mpg

EC extra-urban: 43.5mpg

EC combined: 36.7mpg

Emissions (CO2): 202g/km

For more information visit www.jeep.co.uk