THE letters C and S may sit at opposite ends of the alphabet, but for Mercedes-Benz they are squeezing ever closer.

Such is the determination to keep its global best-seller the C-Class compact executive - more than 2.5 million saloon and estate versions sold since 2014 - on top of the pile, that the company has added various high-tech features from its flagship S-Class.

It's instantly noticeable too. From the moment you step inside the cabin of the revised C-Class saloon the comfort, character, design and tech jump out at you.

Quality is the keyword and the soft leather upholstery of our range-topping Premium Plus variant boasted a light caramel/orange and charcoal colour scheme that dominates the interior and looks really effective as well as being multi-adjustable and attractive.

Central to everything though is the latest generation of MBUX - Mercedes-Benz User Experience - fresh from the S-Class and more digital and smart than ever.

Complete with a high-res 11.9-inch central media display, 12.3-inch digital driver display and Hey Mercedes voice-activated assistant, the set-up is pin-sharp, easy to use and has customised Classic, Sport or Discreet screen styles.

As for interior space there's more elbow room both front and back plus slightly more headroom - without affecting the swooping style of the car - and up to 35mm more kneeroom in rear.

It's quite tight for three across the back and the transmission tunnel doesn't help a centre rear passenger. That said the middle position may look firm and perched but it's actually quite accommodating.

But for driver and front seat passenger it's a classy and cool-looking environment with a stylish carbon-effect lower dash with that huge touchscreen dominating.

Five air vents, three in a row at the centre and one at either side, grace the upper dash area with its supple texture and orange stitching while the chunky flat-bottomed steering wheel is also leather covered.

While there's a choice of petrol and diesel engines along with a petrol plug-in hybrid our tested C 300d featured the higher-powered 265bhp diesel and, like everything in the latest range, included a 48V mild hybrid system.

It features an energy recovery function plus the ability to glide with the engine switched off to boost efficiency, while also adding 20bhp to the overall output.

The upshot is a car that's quick, dynamically superior, agile and exhilarating to drive in no small part due to its rear-axle steering which makes the C-Class feel very stable.

The 300d has an official Combined fuel consumption figure of 53.3 miles per gallon and our own return of 38.4mpg, over 230 miles, was perhaps hampered by being recorded in principally urban conditions.

That apart, this is an extremely appealing car and one that comes packed with kit regardless of model.

Even the entry grade C 200 Sport saloon at £39,860 includes stuff like the MBUX system, 17-inch alloys, LED headlights with adaptive highbeam assist, lane keeping assist, blind spot alert, a parking package, reversing camera, heated front seats and wire smartphone charging.