Hydra-Matic appeared as an Olds exclusive. It provided true clutchless driving with four forward speeds. Its fluid coupling between engine and transmission eliminated the clutch and its associated foot work. Olds made the breakthrough Hydra-Matic available on all models for only an extra $57. In the early 50s, Olds produced its millionth Oldsmobile with automatic transmission, demonstrating Hydra-Matic's rapid rise in popularity. source: 2