The iconic Jeep made its debut 65 years ago.

But far from retiring, the tough Land Rover Defender rival is working harder than ever.

This year sees the first ever diesel models and the arrival of the four-door Wrangler Unlimited version – and we put both the short and long wheelbase vehicles  through their paces at their UK launches in Scotland.

Some cars put a smile on your face – and they don’t have to be expensive performance cars either.

The Jeep Wrangler – along with other affordable models like the MX-5 and the Mini – does just that.

Its off-road capability is breathtaking.

Before supervising my tackling of the muck and bullets portion of the road test, my instructor invited me to take a look at the descent we were about to attempt.

As you can see from the picture (right) - it was steep. But, having driven the outgoing model and knowing what its successor was likely to be capable of, I was nerve-free.

And, sure enough, the Wrangler, held back by engine braking, gently trundled down the bank to the manner born, which of course it was.

The original Jeep was a product of WW2 and has attracted gasps of admiration for its staggering capability ever since.

Now it has undergone radical revisions to produce an all-new version which looks much more modern without destroying its unique DNA.

Both the two and four-door versions look stylish as well as practical.

The traditional hallmarks are there: seven-slot grille, round headlamps and upright windscreen. But these are now complemented by looks which will appeal as much to the SUV fan as to the hard-core off-roaders – as will the interior.

Though far more functional-looking than more lifestyle-orientated members of the Jeep range, the Wrangler makes for a pleasant environment for road journeys, as we discovered on the four-hour round trip to the 4x4 course near Stirling, in Scotland.

There are six models to choose from.

The two-door Jeep Wrangler is available as a 2.8-litre diesel manual or automatic, or as a 3.8-litre petrol model.

The four-door Jeep Wrangler Unlimited is only on offer with a 2.8-litre diesel engine, available as a manual or automatic, with a choice of trim for the manual.

We drove the four-door and two-door models on-road and were impressed by how liveable they were. Noise levels are low, comfort is high and there is of course plenty of power with between 232 and 302Ib/ft of pulling power available across the range.

The petrol version can hit 62mph from standstill in 9.6 seconds, though this increases to an estimated 13 seconds for the long wheelbase diesel automatic. All have a top speed of 112mph.

Jeep says it has improved the steering and off-road we couldn’t fault it. The flipside, however, was this meant on-road, we felt this was one of the vehicle’s weaker aspects and found it a bit vague,

Mostly, however, it is good news – nowhere more so than when the Wrangler, or its bigger brother is able to display its off-road credentials. It is quite simply excellent when steered off the tarmac.

Other improvements include the incorporation of an electronic stability programme – a package of driver aids – which is among the 20 safety and security features included as standard on the new model.

The all-new frame helps the cause by being 100 per cent stiffer than its predecessor.

And, as with other Jeep offerings, buyers get a lot of car for their money with alloys, six-speaker CD/radio and power windows all standard.

We liked the car as we drove it to the course. Jeep really has improved its on-road capability.

But it has lost none of the ability which really lies at the heart of its appeal and that was clear to see on the course itself.

The addition of a long-wheelbase version makes Jeep’s appeal more flexible and worth the consideration of a broader spectrum of motorists – as do it’s winning new looks.

A very serious contender for the Defender.

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