There’s been a changing of the guard in the world of big 4x4s over the past year or so. New designs like the Audi Q7 and Volvo XC90 have delivered much improved fuel economy and lower emissions.

For company car drivers, these new models make a lot of sense, as their lower carbon dioxide figures make them more tax-efficient. For private buyers – and caravanners in particular – the case isn’t so clear cut.

One of the ways that Audi and Volvo have made their big SUVs more economical is by reducing weight. With kerbweights of close to two tonnes, both are comparative lightweights in the world of big 4x4s. That’s great for stretching a gallon of diesel as far as possible, but not so great for matching ratios.

Old-school 4x4s like the Land Rover Discovery and Jeep Grand Cherokee pack significantly more heft. Jeep quotes a kerbweight of 2403kg for the current Grand Cherokee 3.0 CRD V6. That’s around 300kg heavier than the Audi Q7 – or to put it another way, the equivalent of four adult passengers.

The Land Rover is even heavier, but in a few months it will be replaced by a new, lighter Discovery with emissions to compete with the new generation of big 4x4s.

That leaves the big Jeep as one of the last of the old-school 4x4s. It’s not facing newer, greener SUVs unchanged, though, as Jeep has just announced some model year changes for 2016/17 and two new special editions.

The Grand Cherokee now has a start/stop function, which contributes to a 14g/km reduction in the 3.0-litre diesel’s carbon dioxide output, bringing it down to 184g/km. That’s well below the Land Rover Discovery’s 203g/km, but some way off the 149g/km of the most efficient Volvo XC90 diesel. The Jeep’s official combined economy figure has improved to 40.4mpg.

As well as the start/stop system, there’s been a shift from hydraulic power steering to electrical assistance, which will also have improved economy and emissions. 

New colours are available, called Velvet Red, Redline and Ivory Tri-Coat, and the car is now fitted with acoustic glass – think of it as double-glazing for cars – which should make the cabin quieter at speed.

Inside, there’s a new gearlever and revisions to the centre stack. There are also new safety features such as a ‘Stop’ function up to 7mph on the Rear Park Assist, and full speed forward collision warning.

Prices start from £45,050 for the 3.0 CRD Limited+, climbing to £52,550 for the 3.0 CRD Summit.

As well as updating the Grand Cherokee range, Jeep is launching special edition versions of all its models to celebrate the company’s 75th anniversary. The Grand Cherokee 75th Anniversary will be in showrooms by the end of the month. 

As well as all the model-year updates for 2016-17, the 75th Anniversary will come with a long list of standard equipment including external bronze detailing and 75th Anniversary badging, 20-inch bronze-coloured alloy wheels, a new front design, new LED fog lamps, a Safety Technology Pack (adaptive cruise control, forward collision warning with crash mitigation, cross path detection and blind spot monitoring), Quadra-Lift air suspension, a dual-pane panoramic sunroof, a 75th Anniversary seat design with 1941 logo, and black leather with tangerine stitching.

The car will be sold in four colours: exclusive Recon Green, Bright White, Brilliant Black and Granite. The price is £50,550.

Just 125 Grand Cherokee 75th Anniversary cars will be made. Jeep is also making another, even more exclusive Grand Cherokee special edition. Just 30 of the Grand Cherokee SRT Night will be built. 

Based on the fastest Grand Cherokee, the SRT, this special edition is powered by a 468hp 6.4-litre V8. Jeep says the car can go from 0-62mph in less than five seconds, so pulling a suitably matched caravan shouldn’t be a problem…

On the outside, the SRT Night features lots of black trim and black 20-inch alloy wheels. On the inside, there’s black leather trim with black stitching, along with a silver steering wheel bezel and SRT badges. 

What Jeep calls ‘Performance Pages’ are standard, and are displayed on the 8.4-inch UConnect Touchscreen. These have been tweaked to show even more performance timers and gauge readouts, and there are new driving modes so owners can alter the car’s behaviour to suit the surface it is driven on and the conditions.

The Jeep Grand Cherokee SRT Night costs £69,865. That’s serious money, but then the SRT delivers serious performance.