Reengined

Reengined is a term used in transportation and engineering to describe a vehicle whose original engine has been replaced with a newer or different engine during its service life. The intent is typically to restore or improve performance, extend operational life, or meet regulatory requirements. Re-engining can involve changes to powerplant, engine controls, fuel systems, and sometimes airframe fittings, support equipment, or weight distribution, and may require certification by the relevant authority.

In aviation, re-engining is common as airframes age and engine technology advances. Replacing legacy piston or early jet engines with modern turbofans can increase thrust, fuel efficiency, and reliability, while also reducing maintenance. In the automotive sector, mid-life engine replacements are performed to improve power, efficiency, or emissions, and to address design life expectations. In maritime and rail sectors, engine replacement and hybridization can offer reductions in operating costs and compliance with environmental standards.

Economic considerations vary: while the upfront cost is high, long-term savings from better fuel economy, reliability, and lower maintenance can justify the investment, especially where engines are near end-of-life or environmental mandates apply.

Re-engining is a form of retrofit and modernization used in many transportation sectors, and relates to terms such as engine replacement and upgrade.