WHY change an outright winning formula?

That's the question Ford's Mustang backroom team asked themselves when thinking about updating the super-fast sports car which first appeared here in right-hand-drive a couple of years ago.

The answer was quite simple - no radical overhaul but some subtle changes with a few tweaks here and there to further enhance the Mustang's appeal.

The philosophy has worked.

There's still two normally aspirated petrol engines on offer - a 2.3-litre Ecoboost and a 5.0-litre which has now been boosted by 30bhp to offer 444bhp to offer improved performance.

Technically the most notable - and welcome change - is with a new 10-speed automatic gearbox, developed jointly with GM, that replaces the previous, rather sluggish six-speed automatic gearbox.

Key here is that the gearbox ratios change faster and much smoother which mean that the driver can see it dropping down from tenth to third or fourth gear when wanting a quicker acceleration.

Likewise, going back up the gears the shift will go direct, say from fourth to seventh missing out the ones in between - all in the name of being quicker off the mark.

The reality is that this new system works perfectly and now gives the Mustang excellent sports performance and once out on the open road it's even more fun to drive and a genuine sports cruiser at speed.

Official performance figures are right on the nail with the 5.0-litre V8 skipping from 0 to 62mph in just over four seconds with the driver having the option to use the paddles mounted on the steering wheel for manual gear changes which itself is now far more smooth and quicker.

With such improved throttle response drivers will still enjoy that now famous bellow-like exhaust sound when accelerating hard - a real muscular noise - but which drivers too can manually adjust to calm down and not upset their neighbours.

There are six different driving modes starting with normal followed by sport, race track setting, one for overcoming snow and wet road conditions, drag strip driving and finally My Mode which allows the driver to select their own preferred settings.

The shock absorbers have been retuned too to give the Mustang all round improved stability and amongst the new standard driving aids are autonomous emergency braking, pedestrian detection and lane departure warning - all part of Ford's efforts to gain an NCAP 5 star rating which its predecessor did not have.

In terms of looks the new Mustang sees some subtle changes with a slightly sharper appearance at the front and all round LED lights.

Drivers should also opt for the £1,500 new MagnerRide adjustable suspension which certainly helps to improve the overall feel and handling of the car.

The cabin has been tweaked too - the driver can choose from 27 different dashboard readout colours on speed, revs etc., - and the impressive and so easy to use 12-inch digital display complete with SYNC3 infotainment system has again seen minor improvements.

Recaro seats give excellent all round lumbar support and whilst there are two rear seats the Mustang remains officially a 2+2 with only real room in the back for younger siblings to sit in any comfort.

Available as either a hard or soft top and with two engines on tap, the choice is down to the individual with the more conservative buyer opting for the 2.3-litre at £35,995.

But for the real performance connoisseur it has to be the 5.0-litre V8 which comes in at £46,595 with extras on board.

It is more than a better buy compared to some German made rivals and of course it has that distinctive Mustang badging and traditional looks.

This is the sixth generation Mustang and it's without doubt the most exciting sports car to come out of the Ford stable.