M199

The 300 Sc of 1955 was the 300 S brought up to date, and the update that counted sat under the bonnet. Out went the three Solex carburetors; in came the elaborate Bosch direct injection developed alongside the 300 SL, firing petrol into the cylinders themselves, with compression raised from 7.8 to 8.55:1. Output rose from 150 PS to 175 and top speed from 175 to 180 km/h. Mercedes-Benz considered this worth announcing, and had EINSPRITZMOTOR stamped in large letters across the back of the car.

Almost nobody was in a position to notice. The Sc listed at 36,500 DM, 2,000 more than the car it replaced, and between January 1956 and April 1958 exactly 200 were built: 98 coupés, 53 roadsters and 49 Cabriolet A. Direct injection turned out to be a difficult virtue — it thinned the oil with unburnt fuel and the pump was punishing to manufacture — and from 1957 Mercedes-Benz began retreating to the simpler business of spraying into the inlet tract, starting with the 300 d. The M 199 was the last outing for a system inherited from wartime aero engines.