After a long developmental period, Aston Martin replaced the DB2 with the smaller, more experimental DB3. The program consisted of 10 cars that raced for two years.
DB3s were seldom alike. During the first year of racing many different bodies were affixed to the chassis. Some cars had coupe bodywork which proved unstabled at high speeds.
The engine in the DB3 was an evolved version of W.O. Bentley's postwar Lagonda engine. Over the years, David Brown developed the engine, introducing many significant changes.
Unfortuntely, the DB3 never achieved any major success. Most of the races ended up with DB3s retiring with a variety of problems. The Hypoid rear differential was very problematic. Furthermore, even if the cars had proved reliable, they were still trying to keep pace with the Jaguars and Ferraris. The only notable victory achieved was the 1952 Goodwood nine hours driven by Collins and Griffith.
Despite the limited success, the DB3 paved the way for future Aston Martin purpose built race cars. It shorly replaced by the DB3S in 1953. This move kept Aston Martin competitive with cars such as the Jaguar C and D-Type. The DB3S itself transformed into the DBR1 in 1959. Although distant, the DB3 started a program which would eventually end up with an outright victory at LeMans in 1959.