IF that famous Gothic novella The Strange Case of Dr Jekyll and Mr Hyde were to be applied to modern day cars, one would instantly spring to mind.

If there's a genuine Jekyll & Hyde model out there then it is surely the Ford Focus ST.

Of course the Edward Hyde character in Robert Louis Stevenson's story was evil to the core - actually based on wife murderer Eugene Chantrell - and while the Focus ST couldn't be described as evil, it's certainly wicked.

Wickedly quick and devilishly exciting at least.

The latest iteration of the ST, developed under the umbrella of Ford Performance, comes with a hatful of advanced technologies plus the most powerful engines ever seen in this model range.

They ensure drivers have up to 12 per cent more power and 17 per cent more pulling power than its predecessor and, particularly in the case of our tested 2.3-litre EcoBoost petrol variant, the effect is exhilarating.

Delivering a hefty 280ps of punch this model can scorch from 0-62mph in 5.7 seconds and also features the company's first application of an electronic limited-slip differential on a front-wheel drive vehicle - to enhance cornering and stability.

Just to put those figures into perspective, the hatchback has faster in-gear acceleration than the last generation Focus RS.

Four selectable drive modes named Slippery/Wet, Normal, Sport and - for those specifiying the £250 Performance Pack - Track with launch control facility, mean drivers can alter stability, sound and throttle mapping settings to suit the scenario.

The brakes are stronger too, with an electronic booster, and there's also continuously controlled damping which adjusts the suspension every two milliseconds plus super-fast steering response with only two turns lock to lock.

It adds up to a car that has all the power, precision and balance an enthusiastic driver would realistically wish for, but without the full-fat hardcore nature of the Focus RS.

If that little lot represents Mr Hyde, what of the ST's Dr Jekyll traits?

Well the beauty of this car is that while it looks and sounds like a performance model with its body-hugging Recaro seats, unique alloy wheels, angled rear spoiler and twin central tailpipes, it is also very much an everyday family hatch as well.

Cabin refinement is extremely good and accommodating rear knee room is claimed to be best in class, but then the latest Focus also has an appreciably longer wheelbase than before, which itself equates to extra room for passengers.

Then there's a flatter floor beneath the centre seat making the car more comfortable to sit in and the side windows stretch further rearward so passengers also have an unrestricted view out.

As for fuel economy the official combined figure of 35.8 miles per gallon is a tad on the optimistic side - our own average over 200 miles of mixed urban and motorway driving returning closer to 27mpg.