Diesel began licensing his engine design to various companies around the world. The engine quickly gained popularity for its high efficiency and fuel economy, leading to its adoption in various applications, including power plants, ships, and industrial machinery.

Diesel became a well-known figure in the engineering world, receiving numerous awards and accolades for his invention. His engine was hailed as a significant advancement in technology and a major contribution to industrial progress.

Despite the commercial success of his engine, Diesel faced financial difficulties due to poor business decisions and a lack of experience in managing large sums of money. He invested in various ventures that ultimately failed, leading to significant financial losses. Additionally, many early engines did not perform as well as promised and required costly fixes.

Diesel published a book titled 'Solidarismus: Natürliche wirtschaftliche Erlösung des Menschen' (Solidarism: Natural Economic Redemption of Man) in which he outlined his social and economic theories. This book reflected his concerns about the social implications of industrialization and his desire to create a more equitable economic system.

While travelling from Antwerp to London on the passenger steamer SS Dresden, Diesel mysteriously disappeared. His body was later found in the English Channel. The circumstances surrounding his death remain unclear, with theories ranging from suicide to accidental drowning to murder.