How have the kidney grilles of BMW evolved over time?

How have the kidney grilles of BMW evolved over time? The Bavarian brand is one of the easiest brands for anyone to recognise, even people with no great passion for the automotive world. This is possible thanks to its distinctive kidney grilles and the famous Hofmeister kink. This kink is what gives shape to the rear windows. According to the brand itself, “the twin kidney grille makes each BMW perfectly recognisable without the need to check the badge”.

It should be noted that most of the models belonging to the Bavarian brand share a common feature that makes them “special”: the unmistakable front grille. Only the microcars of the 1950s, the BMW Isetta, the BMW 600 and the BMW 700, did not feature it.

The design of this emblem has evolved throughout history, whether due to trends, advances in aerodynamics or engine cooling. What is the purpose of the grille? To channel fresh air towards the radiator to cool the engine properly.

At first, the kidney grilles were narrow, slender and simple; over time they have evolved, as seen on the BMW E30, BMW E36 or BMW E46, and have continued to grow up to the present day. They now offer “a complex, asymmetrical, three-dimensional and customisable design”, reflecting the evolution of the brand’s design language. The latest advance in this constant evolution is the illuminated kidney grille of the upcoming BMW X6.

The history of a brand tied to its kidney grilles

Only three BMW models were built before the iconic grille was introduced. Two of them were the Dixi 3/15 PS and Dixi 3/15 PS DA, built under licence from Austin Seven. The third is the BMW 3/20 PS, the first and only car fully built by the brand without its characteristic grille. After them, in 1933, came the BMW 303, which already incorporated the famous grille.

The first BMW models to use this iconic design element had a grille very different from the one we know today. The two kidneys had an elongated, narrow design and occupied the entire front of each model. The two kidneys featured chrome frames and a metal mesh on the inside.

The BMW 315/1 of 1934 already showed a more inclined and aerodynamic front grille. But the first major evolution of this element came with the elegant BMW 328 roadster of 1936, designed by Peter Szymanowski. In this model, the front wings and the headlight housings gained surface area on the front, which was no longer exclusive to the radiator and grille area. The grille showed a curved design, influenced by aeronautical design and advances in aerodynamics. The chrome frames were more flush with the bodywork, and the inner mesh had a more elaborate pattern with five large vertical bars per kidney. The legendary BMW 328 Mille Miglia Touring Coupé took that configuration to the extreme, with thinner kidneys, four bars inside and a black background.

A distinguishing element

We had to wait until the 1990s to see a new interpretation of this element, which shaped kidney design up to the present day. The kidneys of the 1990 3 Series had a clearly trapezoidal design, with the upper part wider than the lower. In addition, they were wider, had very rounded edges and protruded from the front with a three-dimensional effect. Much earlier, the sole BMW Garmisch of 1970 already featured hexagonal kidneys.

The BMW 5 Series of 1996 introduced another styling feature used until recently by most of the brand’s models: the “kidney grille” was integrated into an extension of the bonnet, which descended until it touched the bumper.

The grille has steadily gained size and prominence on the front of every BMW, whether on the new X series that debuted with the BMW X5 of 1999, across the saloon and coupé range, or even on the BMW i, where a “matt” grille underlines that there is hardly any need for cooling. The extreme example is the BMW X7 and the BMW 7 Series, which feature the largest grilles; that of the new BMW 7 Series has grown by 40% compared with its predecessor. This increase in size has meant that its placement is now “embedded” between the bonnet and the front bumper, encroaching on space from both.

According to BMW, “the designs are increasingly elaborate, with more complex and asymmetrical shapes extending towards the flanks. Another car ahead of its time, the BMW 507 of 1956, already presented such a design, with a very wide grille of enormous dimensions and asymmetrical shapes. The finish of the bars and frames is also receiving ever more attention, and they can be personalised with different finishes to highlight the character of each specific model version. These new designs also contribute to the aerodynamic aspect thanks to active shutters that open and close depending on the engine’s thermal requirements”.