AUTOMATIC stop/start is a great emissions and fuel saver in many cars, but in some, it doesn't operate properly.

I've driven three or four recently where you have to keep your foot on the footbrake - and probably blind the person behind at night with your brake lights - if you want it to work.

As soon as you take your foot off the brake and put on the parking brake, the engine starts up again.

Surely, the stop start should operate even when the parking brake is on and the gear is in neutral. In a manual car stuck in traffic, I don't want to have to keep my foot on the clutch for minutes on end.

All this was reinforced when I drove the latest rough and tough Jeep Renegade Trailhawk, the most expensive model from the range.

The Renegade is the smallest car Jeep makes and it shares running gear and engines with cars from the Fiat range.

Trailhawk is the name Jeep uses for all its tougher, off-road equipped models and this top model looks the part, with a butch, square shape that ignores aerodynamics completely.

It's also adorned with lots of black plastic mouldings to help protect the body off-road and has raised suspension to give extra ground clearance.

It is available with just one engine option and comes with ‘proper' four wheel drive (4WD).

The engine is the Fiat 2.0-litre turbo diesel, here boosted to 170bhp and driving through a standard nine-speed automatic gearbox.

There's plenty of power for on and off-road use and this would make a superb towcar for a caravan or trailer.

But take it for a test drive before you buy - a good few miles would be best.

That's because the engine is pretty noisy on the move, even when it's warmed up, and it's not that smooth either at times, passing vibration through to the cabin.

That said, it is happy to rev - more than many other diesels - and performance is very good, with the 0 to 60mph sprint coming up in just 8.2 seconds.

It's also more economical than other SUVs capable of heavyweight off-roading, managing an average of over 47mpg on the Government cycle.

The gearbox is a high spot, with a gear for every occasion and a few to spare. Kickdown is reasonably quick, but for best progress when in a hurry it's better to use the manual setting and the floor mounted selector.

However, it doesn't get into the fuel sipping ninthgear until it is above 60 miles an hour and won't let the driver select it at lower speeds.

The 4WD system has a mode for all reasons and is adjustable from the driver's seat to give standard automatic and best electronic settings for mud, snow, sand and rock.

It can tackle the most severe off-road terrain and even comes with proper low ratio gears and a centre differential lock for maximum traction.

With such an angular shape there is a good deal of wind noise at speed on the road and there is also noise from the tyres on many surfaces and bump thump over potholes and drain covers.

Surprisingly, it doesn't roll too much in the corners and so holds the road well, but it's not really built for fast cornering.

It's built for off-road or towing use and to keep you going in the winter when everyone else is floundering.

There is decent support in the seats and they are comfortable over longer distances and both height and reach adjustable steering and height adjustable seat work well, making a very comfortable driving position.

Standard kit in this range topper includes hill descent control, electric parking brake with auto off, keyless entry and starting, parking sensors and a camera, stability control, climate, leather upholstery, DAB stereo with Bluetooth and aux-in, voice activation and a multi-function steering wheel.

As a workhorse for a farm, or to pull a caravan or a trailer, or get essential people where they're going in the worst of winter, few cars would be better.