Its shorter wheelbase enabled a relatively lightweight compared with its 2.5 tons predecessors, thus the 7-litre supercharged straight-6 with 225hp output enabled a very impressive power-to-weight ratio for its time. Although a test carried out by Motor magazine found a disappointing top speed, its competition success in hillclimbing events (such as Mille Miglia) and many other events including the 1930 Irish GP proved its real ability.

Perhaps too emphasised on power, its brakes were quite unable to stop the car effectively. Its handling, although decent for a 1920s sports car, immediately became unacceptable as the lighter, smaller Alfa Romeo 8C 2300 arrived.

Both 500K and 540K were not serious sports cars, unlike the SSK. Although the supercharged engines still developed remarkable 160 and 180 hp respectively, excessive weight of over 2 tons limited their performance. In fact, they were real Grand Tourer. Quality, elegance and comfort were their biggest concern. Today, after 60 years, while Alfa Romeo and Bugatti are causing so much headache to the restorers, Mercedes 500K/540K is proved to be the most durable pre-war car.

From the beginning, 300SL was designed for racing purpose. Therefore it adopted tubular spaceframe construction for the chassis. Tubular spaceframes, though light and rigid, had one draw back, that was, it engaged considerable space originally provided for doors openings so that door sills had to be made considerably higher and wider. As a result, engineers installed a pair of gullwing doors instead, which also opened the roof for easier access. Such innovative design immediately received admiration from all over the world.

The powerful straight-six was fed by a mechanical fuel injection, which was probably the earliest one employed. Displacing just 3 litres, it output an outstanding 215 hp. Since this engine was quite tall, in order to keep the bonnet as well as centre of gravity low, engineers had to tilt the engine for 40°, and then offset to one side.

300SL was a fast machine, but it was as difficult to control as racing cars. Its swing axle rear suspensions gave the sort of high speed oversteer that only a really gifted driver could cope with. However, once the driver overcame that, he could enjoy the racing car performance that other cars hardly matched.

When the engine was enhanced to 2.5 litres and 197 hp, 190E 2.5-16 became faster. But it was still a rather civilised sports sedan. Build quality was as satisfying as the three-pointed star suggested, the individual leather bucket rear seats were great to look at and sit in. Combined with fine performance and handling, 2.5-16 was a very all-round sports sedan, although hardly qualified as a classic car.

What impressed me was the Evolution II which was created to homologate DTM German Touring Car Championship (WTCC had already been discarded). The car was modified by AMG, pumping the 2.5 engine to 235 hp at 7200 rpm (race car: 373 hp @ 9500 rpm). Though displaced in similar size, the four-pot has larger bore and shorter stroke than 190E 2.5-16 to enhance power. The tracks were widened accompanied with aggressive wheelarches extensions which housed 245/40ZR17 tyres. An even more aggressive huge rear wing was used to generate massive downforce. Since the late 50s, Mercedes had never created such a serious performance car. AMG built just 500 cars to meet the minimum requirement of regulations.