A look at the generations of BMW M3 and M4 Convertibles.

From the outside it’s an attractive convertible, but under the bonnet there’s the 2.3-litre high-performance engine. The cylinder head, for example, is related to that of the M88 engine from the legendary BMW M1. The water-cooled 4-cylinder inline engine with the compact construction with 16-valve aluminium head, two overhead camshafts and a crankshaft supported by five bearings had 195 hp at its market launch and achieved a top speed of 228 km/h. In the summer of 1989, another 20 hp were added and the top speed rose to 239 km/h. For the time and compared to the competition, fantastic figures for a four-seater convertible.

Only 786 of the open BMW M3s were manufactured, making the Convertible one of the rarest E30 models ever and a sought-after classic.

From the start, the BMW M3 E36 was optically more restrained. Those unfamiliar with the details of the top model of the E36 series may not see the vehemence hidden under the sleek bodywork. The giveaways are the aerodynamically elaborate M wing mirrors which reduce drag measurably, new skirts front and back and special 17-inch wheels. BMW M also lowered the suspension of the high-performance 3-series by a good 3 cm. This new proximity to the asphalt not only brought benefits for the cars’ centre of gravity and driving behaviour, the makeover gave the M3 a squatter, fuller stance on the road than its more civil siblings.

The BMW M3 E46 was immediately seen as the top model of its series. In particular, the optical alterations like wider wings, special side sills and new front skirt unmistakeably defined the M3 as a high-performance vehicle. Fun fact: The striking chrome gills in the wings were not conceived as design elements, but that’s what they became. Originally designed to be air outlets for cooling the engine, during testing it transpired that air outlets weren’t necessary. The gills stayed – and became an optical highlight admired not only by BMW M fans.

For the drive unit of the fourth generation of convertibles, the engineers at M GmbH transferred the high-rev concept to a V8 engine. Beside the high power output of 420 hp, what impressed more than anything was the new engine’s linear performance characteristic. On top of that was the unmistakeable and with the top down clearly audible sound of the 8-cylinder engine. With a 4-litre capacity and maximum torque of 400 Newton metres, it looked very strong on paper. What was especially impressive were the peak revs: 8,300 rpm, which heralded every gear-shift with a rousing racing car soundscape. Together with the double-clutch transmission M DKG, available for the first time, the BMW M3 Convertible sprinted from 0 to 100 km/h in just 5.1 seconds.

One further premiere with the E93 was the electro-hydraulic metal folding roof. The new roof construction added year-round suitability to the high-performance car’s racetrack affinity.

In 2016, M GmbH upped the ante again in terms of dynamics and performance. For the first time, the M4 Convertible could be ordered in the Competition version, which had several changes to the drive unit and suspension: The engine of the Competition model was given a performance boost of 14 kW (19 hp) to 331 kW (450 hp), the Adaptive M suspension was fitted as standard and new mapping for the exhaust system meant a more emotional sound. Thus invigorated, the M4 managed the sprint to 100 km/h in just 4.3 seconds. For maximum speed, the M Driver’s Package was available, with a top speed of 280 km/h. The hitherto last series of the BMW M4 Convertible thus offered ideal conditions for maximum performance on the racetrack and effortless everyday driving pleasure.