The 1930s saw rapid improvement in aircraft performance and great increases in size. In 1934, even before the new Jumo 210 had completed its acceptance tests, the RLM sent out a request for a new 1,000 PS (986 hp; 735 kW)-class engine of about 500 kg (1,100 lb) weight. Both Jumo and Daimler-Benz responded, and in order to reach service before the new Daimler-Benz DB 600, the Jumo team decided to make their new design as similar as possible to their 210H model, currently in testing.