WE have all done it: ask a pub-mate what car they think of in a particular brand and one of the most popular which pops into mind is the BMW 3 Series.

It really put the Bavarian brand on the roadmap to success in the 1970s and it is the standard, the benchmark, for not only that size of car but even the culture of ‘the company car'. It has transcended just being a car to being iconic.

Revised styling and interior trim in 2015 together with some subtle engineering improvements and the BMW 3 Series stays at the top of most wish-lists.

The mid-range 320d M Sport combines the best of economy and performance and delivers them in an attractive package which allows the driver to select how he or she wants the car to respond or perform.

Deep in its computer brain are performance maps which the driver can explore if they want a sporting, normal or comfort/ economy mode and which selection can produce very different responses and dramatically change the car's character.

Sharp, subtle or smooth are available at the touch of a button and graphically illustrated to underline what you feel is going on.

The four-cylinder turbo-diesel 2.0-litre is a highly refined engine delivering a smoothness normally found in a six-cylinder unit, with remarkably good response, a wide power band and a hefty push of power when needed.

Allied to the slick and tight six-speed gearchange with a long travel clutch, the powertrain gives effortless performance for ease of driving in town or country.

Carefully choosing the driving modes over a mixture of roads meant we averaged mid-50s for fuel consumption and event saw it head towards 60mpg at times.

Everything sharpens up in the sporting mode and you can make the most of the power in complete safety and with confidence inspiring steering and brakes underfoot.

It rides smoothly nearly all the time, only really bad potholes shake the shell and its wide track allows it to straddle many speed pads without a problem.

Grip is very surefooted and the handling utterly faithful to driver input so you are never left thinking what the BMW 320d M Sport is going to do.

Its M Sport trim on seats and inside lifts a slightly drab finish despite the best efforts of the stylists to include lots of curves into the fascia.

Dials and secondary controls are clear and work well, the automatic air conditioning is nearly silent but so sophisticated and oddments room is reasonable but not outstanding. It all looks and feels very well put together.

Access is straightforward with wide opening doors and even rear legroom is good for an average sized occupant while the front leather-covered seats have enormous adjustment range, excellent shaping and support.

The boot opening is not huge but the capacity is a very useful 480 litres behind so it comfortably takes a few cases or golf bag.

It comes with rear radar to aid parking but its hardly necessary because the vision is really good all-round with very bright intelligent long-range headlights and very quick wipers when raining.

Noise levels are low from all sources but possibly the most obvious is the road rumble from the wheels and tyres and even that is not intrusive, just in the background.

It's easy to appreciate why the BMW 3 Series is so iconic, why so many look up to it and seek ownership or comparison.