Throwback Thursday: 1955 Mercedes-Benz 300 SL road test

Suspension at the front was by coil springs and double wishbones, while the rear had an independent set-up of coil springs and swinging half-axles.

On 25 March 1955, Autocar got behind the wheel of this "most astonishing" car. We began: "This coupé is in full production for sale to those who have the ability to handle and the means to purchase such a car. As is well known, the two essentials do not often go together."

After completing the awkward ingress over the very high sills, we found the 300 SL's driving position offered "an extremely good view", with the sloping bonnet "allowing the driver to see the road close up to the car", the driving position adjustable enough for most and the steering wheel "placed at an ideal angle".

We continued: "The 300 SL is docile and tractable in dense city traffic, but there is no doubt whatsoever that its true place is outside built-up areas, where it can be allowed to come into its own.

"After it has trickled along in third and top gears, the time eventually arrives when second gear can be selected, so that the car really comes to life.

"For a passenger who has not travelled in the 300 SL before, the effect is electrifying. The occupant receives at first a mild pressing back into the seat and then, as the power comes in between 3500rpm and 400rpm, he feels as though he is being rocketed through space. Up to 70mph is available in second gear, and then comes a quick movement into third. The rev counter needle drops back for a second or two and, again at 4000rpm, the effect of being urged forward by some irresistible force is felt. 

"There is a somewhat harsh note from the engine, but little exhaust and wind noise.

"The acceleration is truly remarkable. The effect up to 60mph is not so noticeable as higher up when, with over 80mph showing, the rev counter needle swinging round rapidly towards the limit mark and third gear still engaged, the car fairly rockets forward.

"Press the accelerator well down even at over 100mph in top gear and, again, there is the feeling of being on the end of a rope that is being pulled hard from in front of the car. The way the 300 SL does it all with so little fuss is almost uncanny."

Our recorded acceleration figures were 0-60mph in 8.8sec and 0-100mph in 21.0sec. A top speed of 135mph was achieved.

"The 300 SL's cruising speed is limited not by mechanical factors, but by the road and traffic conditions," we wrote. "It's one of the least tiring cars to drive, in the manner of all high-performance cars except those which are very noisy.

"The acceleration capabilities of the car enable the driver more frequently to overtake slower-moving traffic in safety and so cut the time for a known route by a very considerable margin and with no feeling of having misbehaved by upsetting other road users. Admittedly, they may have wondered what it was that passed them but, by that time, the 300 SL is over the hills and far away!"

Of course, a car such as this must have the ability to handle and stop as proficiently as it can hurtle. Thankfully, the 300 SL did so, and this we considered "part of the character of the car".

"The ride is by no means harsh," we said. "In fact, on one 400-mile journey, a small child was able to sleep curled up on what is essentially the luggage space behind the seats.

"When cornering at the speed of other traffic, the 300 SL goes round firmly on the proverbial rails, taken close to the chosen line and with hardly a movement of the steering wheel."

Indeed, due to lock-to-lock being just two turns, our driver found himself hardly conscious of turning the wheel in order to corner, reminding him "of a fast motorcycle" that "is steered more by leaning the body than by actual movement of the handlebars".

There was a useful amount of kickback from the front wheels and apparent oversteer; "any inclination to ease the throttle round a corner and the rear of the car will tend to swing round". When driving the car round bends, "no trace of misbehaviour" was noted.

We elaborated: "When taking open, very fast swerves, the driver can start to guide the car round just before he enters the corner and then, using the throttle, make the 300 SL come out on the straight in a beautiful movement.

"There is the typical Mercedes-Benz feeling of the swing axles working. On wet roads, the car slides slightly but, with judicious handling, there is no tail breakway. This is a car that teaches its lessons sharply and thus demands respect."

The brakes, meanwhile, were vacuum-servo-assisted and "fully capable of dealing with the high performance of the car". We found, even when used repeatedly on a rapid descent and when taking performance figures, "there wasn't the slightest sign of fade or unevenness", while the pressure required was "comparatively light".

And that other crucial component, the gearbox, had a pleasant gearshift and a smooth clutch that had no slip.

Clearly, Autocar's testers were stunned at this car – after all, it was the fastest production car at a time when traffic would have consisted of Austin Sevens and Morris Minors. Looking back now, it's easy to see why the 300 SL is often billed as the "first ever supercar" and now sells for more than £1 million (rather than the £4392 demanded in 1955).