On 17 May 2013, Honda announced their intention to return to the sport in the 2015 season under a works agreement with McLaren to supply V6 engines and kinetic energy recovery system (KERS) units. The first iterations of the Honda engines proved to be unreliable, fuel thirsty, and underpowered, with Honda admitting they returned too early, taking on a project they were not ready for; due to this, Honda spent their first 3 years under the harsh scrutiny of the public eye as they developed their PU. McLaren split with Honda after three years when Honda advised they would not have a front running power unit until 2019 at the earliest, Toro Rosso however, agreed to use Honda engines for the 2018 season as a works outfit. Following a fairly successful season with Toro Rosso, Honda showing fast and potent development with the engines which were proving to exceed the performance and reliability of the competing Renault units, the parent team Red Bull Racing agreed to also take on Honda engines for the 2019 season replacing Renault. So far at the start of the 2019 campaign, Honda engines have proved reliable and fast, greatly reducing the gap to the leading Mercedes and Ferrari power units. Their first victory of the hybrid era was at the Austrian Grand Prix.