The descendant of the original US Army workhorse has been completely redesigned.

Already on sale in its home market, the JL-generation Jeep Wrangler will reach the UK this summer. Once again, it's available in two-door or four-door form, and we drove the latter in range-topping Rubicon guise on and off-road.

The styling is best described as evolutionary; you mess with the Wrangler’s looks at your peril, so LEDs are incorporated into the signature round headlamps and the seven-slot grille bends over halfway up to keep the air attached as it flows over. This design tweak is one of several features that deliver a fuel-economy-boosting 9% reduction in aerodynamic drag over the outgoing, 12-year-old JK-generation model.

The contemporary approach to a traditional formula extends into the vehicle architecture. A ladder-frame chassis and Dana solid axles are retained but Jeep has used high-strength steel to take around 45kg out of the frame. It’s part of an overall 90kg drop in weight, despite the new car's slightly increased dimensions and additional equipment.

An all-new electrical architecture brings the Wrangler bang-up-to-date, not only in features like the Uconnect infotainment system and USB-C port, but also through driver assistance technology such as a reversing camera and blindspot monitoring. In a neat touch, four auxiliary switches on the centre stack can be configured via the 8.4in touchscreen to run aftermarket off-road accessories such as floodlights and foglights.

Two petrol engine options are currently available in North America, the 3.6-litre V6 driven here and a turbocharged 2.0-litre four-cylinder with Jeep's eTorque 48V mild hybrid system. The latter shares a block with the Alfa Romeo engine of the same capacity but has a dual overhead camshaft head rather than the MultiAir one. UK buyers will have the choice of the 2.0-litre petrol or a 2.2-litre diesel.

The V6 is fine when crawling over off-road trails, but peak torque doesn’t arrive until 4800rpm, and on winding roads or hills you have to row the gears of the new-but-notchy 6-speed manual gearbox to maintain momentum. All UK-bound Wranglers will get an eight-speed automatic gearbox, however, and we’d expect the combination of the turbocharger and eTorque electric motor to take care of the missing low-end oomph (and use less fuel in the process).

Road manners are much improved over the JK. The new electrohydraulic power steering is light but has a more precise, car-like feel, while the Rubicon's all-terrain tyres are impressively quiet and there’s far less body roll than you might expect. The front anti-roll bar can be electronically disengaged off-road. We’ll need to see how the ride comfort shapes up on UK roads, but the initial signs are good.

On a challenging trail in a Rubicon equipped with the eight-speed automatic ’box, the ride quality and sheer effortlessness exposed car-like SUVs as the pretenders they really are. The JL Wrangler’s performance is further extended by higher approach, departure and breakover angles than the JK and by the introduction of a hill descent control that uses the shifter’s manual shift function to control the speed of descent.

Meanwhile, the electric portion of the steering’s assistance and a tighter turning circle make it easier than ever to plot your course – and to park when you reach the top of the mountain.

The on-road improvements and additional equipment, together with ergonomic upgrades to the soft-top and passenger accommodation, make this the most everyday-usable Wrangler yet.

Jeep appears to have addressed some of the car's shortcomings without compromising its off-road DNA, and that’s important because, unlike most SUVs, around 90% of Wrangler owners take their cars off-road at least once a year. If you plan to be among them, the Jeep has few rivals to its capability.

Reliability might be a concern for anyone using the new electronic systems in extreme conditions, however. It’s too early to know whether those concerns might be justified, but Jeep's engineers have gone out of their way to keep it all functional, no matter what. Anything electronic within 76cm (30in) of the ground is fully waterproof and the Wrangler had to pass a 16-hour misting test that simulated being left out in a storm with the roof and doors off. Extreme testing for an extremely good extreme vehicle.

Graham Heeps

Jeep Wrangler Unlimited Rubicon specification

Where Malibu, California, US Price £40,000 (est); On sale Summer 2018; Engine V6, 3604cc, petrol; Power 285bhp at 6200rpm; Torque 260lb ft at 2750rpm; Gearbox 6-spd manual; Kerb weight 1912kg; Top speed tbc; 0-62mph 7.0sec (est); Fuel economy 23mpg; CO2 285g/km; Rivals Land Rover Discovery Sport, Volvo XC90, BMW X5