On 9 May 1937, the 750 kilogram W 125 racing car from Mercedes-Benz celebrated its racing debut with a victory at the Tripoli Grand Prix. Following this opening triumph, it went on to dominate the entire season – yet it would prove to be its one and only season. This was because 1937 was the last season in which the 750 kilogram weight limit was the formula applied for the Grand Prix European Championship. The drivers from the Stuttgart-based racing team won four of the five Grand Prix races that counted towards the European Championship in the W 125. This included two 1-2-3 and two 1-2 finishes. At the end of the season, Rudolf Caracciola was crowned European Champion for the second time. The W 125 also racked up some great successes in other races and on record-breaking drives.