THE third generation of the Mercedes-Benz A-Class is on sale now and the sporty compact motor comes with a raft of changes offering more power, greater efficiency, increased comfort and subtle styling enhancements.

Sales of the A-Class in the UK have been booming, with around 60 per cent of buyers being new conquests from other marques and in the first six months of this year 17,000 have opted for the sleek, powerful Merc, and the newcomer looks like boosting this even further.

A major change for the latest A-Class is the introduction of a Dynamic Select system on Sport specification models and upwards, which enables the driver to change driving modes to suit the road conditions.

It offers four driving modes: Comfort, Sport, Eco and Individual with the system modifying the engine, transmission and steering.

Using the Performance Exhaust button you can also change the note from normal to a rasping, spluttering, barking sound when accelerating hard or changing down.

Already offering a wide range of engines, all have been upgraded and are more fuel efficient and cleaner with, for example, the A 180 diesel, which will be a popular choice, is now claimed to offer 80.7mpg on a combined run and CO2 emissions of just 89 g/km.

Further model changes, of many, include the availability of the high-performance A 250 AMG with a six-speed manual transmission, and 4MATIC all-wheel drive can be specified as an option on A 220d models.

Top of the range, and a real mind-blower, is the AMG A 45 4MATIC which now has an output of 381bhp, giving it astonishing performance with a 0-62mph time of just 4.2 seconds, but Mercedes claim it will return 40.9mpg if driven frugally (but who will?). This is the most powerful four-cylinder production car in the world and can hit close to 160mph!

I chickened out on trying to attain this on a German autobahn, but if its stunning top speed, acceleration and exhilarating driving you crave then the near £40,000 price tag is what you'll have to pay.

All new A-Class models I drove on the test drive offered pin-sharp handling, especially on tight bends taken at speed, and with the advantage of the Dynamic Select system all surfaces were easily ironed out to give a smooth, comfortable ride. Also the aerodynamics of the new Merc means there is very little wind noise and intrusive engine noise is well suppressed.

Obviously you want great handling and performance from the new A-Class but Mercedes hasn't neglected upping the equipment level or the outward styling of the sporty, four-door compact.

In the UK, trim levels are SE, Sport, AMG Line and AMG, and the new generation has a diamond shaped grille, revised tail lights, more angular front bumper and a new rear bumper with integrated exhaust pipes.

Standard safety features on the new A-Class include Collision Prevention Assist Plus, a drowsiness detection system, acceleration skid control, brake assist, ABS anti-locking braking system plus an option of lane-keeping assist and blind spot assist. Stop and start systems and standard on most models.

Inside the cabin Mercedes has introduced a larger eight inch central telematics screen (seven inch on SE) which offers drivers control of infotainment, sat nav and many other features.

I also liked the feel of the grippy new steering wheel with multi-function controls and paddle shift gearchange on high-end models.

Prices for the new A-Class start at £22,065 for the A 180 manual petrol version but even then it offers a goodly range of standard equipment, including 16in alloys, seven airbags, speed sensitive power steering, sports seats, Audio 20 radio/CD with six speakers, telephone keypad, Bluetooth, USB port and pre-wiring for Garmin sat-nav system and reversing camera.

I can't see Mercedes going wrong with this new motor even if there is fierce competition from the likes of BMW and Audi.

It is a quality piece of kit which will appeal to the younger driver who is looking for exhilarating performance in a car with classy looks and a comprehensive technical array.