The Renault E-Tech R.E. Series (previously known as Renault Energy F1, Renault R.E. and Renault E-Tech) is a 1.6-liter, hybrid turbocharged V6 racing engine developed and produced by Renault Sport F1 in partnership with Mecachrome for use in the FIA Formula One World Championship from 2014 until 2025. Initially conceived for the regulation changes of , Renault's hybrid power units feature electric motors specialised for recovery of kinetic energy, titled the MGU-K, and one for recovery of heat energy, titled the MGU-H.
The turbo-hybrid engines served as a replacement for the outgoing Renault RS27 naturally-aspirated V8 engine, which had been in use since . The engine was first unveiled on 21 June 2013, during the 2013 Paris Air Show.
At launch, Renault engines were utilised by Red Bull, Red Bull's sister team Scuderia Toro Rosso, Lotus (the rebranding of the former Renault works team, also known as Team Enstone), and Caterham. However, the engines suffered a reliability and performance deficit against their competitors' faster power units, leading to a public breakdown of trust between Red Bull and Renault; from to , Red Bull's power units were badged with the name of the watch company TAG Heuer. McLaren began to use Renault power units in 2018 and switched to Mercedes units in , leaving Team Enstone's then-new brand of Alpine as Renault's sole works supplier. Due to the continued deficits against other power units, as proven by Alpine's poor performance and reliability, Renault officially announced that they would be pulling out of Formula One engine developments after the season - ahead of the 2026 regulation changes - with their historic Viry-Châtillon factory being repurposed as an engineering centre for Alpine and Renault cars. Despite pulling out of engine development, Renault's branding remains on the Alpine A526.
The Renault Energy F1-2014 was Renault's first-ever V6 hybrid turbocharged Formula One engine for the 2014 season. The Renault Energy F1-2014 engine was developed by Renault with technical support from Mecachrome for design research & development, trackside support, engine arrangement, preparation, tune-up and engine maintenance. The Renault Energy F1-2014 suffered reliability problems during pre-season testing.