Some say that life begins at forty. Barring any unforeseen developments, that will certainly apply to the BMW 3 Series. Not that the first half of the compact sport sedan’s life has been dull and insignificant – the 3er created the segment and has been the benchmark ever since. It is desired by many, winning new devotees to the temple of Bavaria with each generation.

It all started 40 years ago when Munich needed to replace the BMW 02. In July 1975, BMW rolled out the first 3 Series, a two-door sedan with a compact footprint and a sporty character. The E21 was powered by four-cylinder engines (1,573, 1,766 and 1,990 cc) with 316, 318, 320 and 320i model designations – ‘i’ stood for fuel-injection in a day when carburettor engines were the norm. Two years later, the segment’s first six-cylinder engine (320 and 323i) was introduced with all-round disc brakes.

A sporty drive was delivered by the E21’s McPherson front axle and independent wheel suspension on trailing arms and spring struts at the rear. The car’s cockpit was inclined towards the driver, and this feature has remained a BMW trademark till today.

You’ll spot an E21 on a lucky day, but the next-gen E30 is a more common sight. Still very compact by today’s standards, the E30 introduced a four-door sedan bodystyle (1983), a convertible and the first M3 (both 1985), plus a wagon in 1987. In addition, the first diesel (324d) and the first four-wheel drive (325iX) models were rolled out. The range expansion was very successful – more than 2.3 million units were sold from 1982 to 1990. Our Harve Singh owned a 1983 320i Coupe.

The next chapter was a big leap in sophistication and size. The E36 was launched as a four-door sedan in 1990, with a coupe following in 1992 before a convertible and the second BMW M3.

New six-pot engines came with two camshafts and four valves per combustion chamber, and VANOS made its debut in the E36. Also new to the nameplate was the 3 Series Compact of 1994, a stubby-tailed hatch based on the E30. Yours truly had an affair with a 1996 328i Sedan, still my favourite booted 3 Series shape.

The fourth-gen E46 (1998-2005) was an evolution of the E36, introducing more comfort and refinement to the familiar package. Innovations included double VANOS for a beefier torque curve and reduced emissions, common rail injection on the 330d diesel and the throttle-free load control system Valvetronic. Also new was an xDrive system that operated without conventional locking, the task being assumed by automatic, wheel-selective brake intervention instead.

We now come to the fifth-gen E90, which in our books, brought the Series back to its sportier roots. Efficiency was all the rage back in the noughties, and BMW launched its Efficient Dynamics strategy for better fuel economy and low emission levels in the E90’s era. High Precision Injection was combined with TwinPower Turbo and Valvetronic in the 335i. Brake energy regeneration and auto start stop were also introduced.

Nice and clean, but for this writer and colleague Jonathan James Tan, this generation’s E92 M3 and its 4.0 litre naturally aspirated V8 motor will be forever missed.

The current chapter in the 3 Series book is today’s F30. The competition has never been stronger, and to defend its turf and cover all the bases, Munich has introduced an unprecedented number of variants to fill every niche.

Sedan and Touring aside, there’s now a 3 Series Gran Turismo for those who want a something between saloon and estate. Coupe and Convertible models have been spun off to to the new 4 Series family, which now also includes the 4 Series Gran Coupe, essentially a four-door coupe offering more style than a plain old 3er Sedan.

The F30, unveiled in 2011, has just received its mid-life facelift. Not much difference in terms of looks, but the LCI gets improved engines and a new range-topping 340i model with 326 hp and 450 Nm. 2016 will see the introduction of a new 330e plug-in hybrid. Read all about the F30 LCI here.

Happy 40th birthday, BMW 3 Series. From fans, ex-owners and the rest of us at Don’t worry, because life begins at forty.

1975 E21 BMW 3 Series

1982 E30 BMW 3 Series

1990 E36 BMW 3 Series

1998 E46 BMW 3 Series

2005 E90 BMW 3 Series

2012 F30 BMW 3 Series