Ecotec (capitalized ECOTEC, from 'Emissions Control Optimisation TEChnology') is a General Motors (GM) trademark that refers to a series of emissions technologies that were implemented throughout a range of GM engines. ECOTEC can refer to the following diesel and petrol engines produced by General Motors:
- Ecotec Family 0 - straight-4 DOHC engines produced by Adam Opel AG and GM Powertrain US.
- Ecotec Family 1 - straight-4 DOHC engines produced by Adam Opel AG, GM Korea, and GM do Brasil.
- Ecotec Family II - Straight-4 all-aluminium DOHC engines produced by Adam Opel AG, GM Powertrain US, GM do Brasil, and Holden Engine Company.
- Ecotec V6 - a version of the Series II 3800 V6 engine, produced by the Holden Engine Company between 1995 and 2004.
- CDTI Ecotec - common rail diesel engines for Opel/Vauxhall cars (Common Rail Diesel Turbo Injection):
- originally designed and produced by Fiat (MultiJet) and currently produced by Adam Opel AG;
- produced by Isuzu (Circle L).
- VCDi Ecotec - common rail diesel engines for Chevrolet and Holden cars, produced by GM Korea (a licensed VM Motori RA 420 SOHC and Family Z).
- DTI Ecotec - diesel engines for use in Opel/Vauxhall cars, produced by Isuzu (Circle L) (Diesel Turbo Injection)
- SIDI Ecotec - petrol Medium Gasoline Engine produced by Adam Opel AG (Spark Ignition Direct Injection)