After three years of hardship, Honda entered a season of renewal with Toro Rosso as its new partner. Honda’s F1 organization was revamped with Yasuaki Asaki as development director of HRD Sakura, Toyoharu Tanabe as trackside racing director, and Masashi Yamamoto as managing director in charge of negotiations with the teams and others. Asaki and Tanabe were engineers from Honda’s second F1 era, and the aim was to move from a hierarchy of a single team principal, to three at the top with divided rolesto ensure prompt and high quality activities in each area.

Once the joint venture with Honda was decided late in the previous season, Toro Rosso rapidly built the STR13 to accommodate the Honda power unit. The STR12, which complied with the new chassis regulations from the previous year, was modeled after the Mercedes cars that dominated, with a high-mounted front suspension upper arm and a wider, three-part induction pod opening to accommodate the high speeds achieved by the wide body.

2018 saw the introduction of the HALO cockpit safety device mandated by new regulations. Although the STR13 was developed as a direct descendent of the STR12, the weight balance due to HALO installation and the move from Renault to Honda power units were unexpectedly large burdens on development. The RA618H was a compact engine, but its turbocharger layout was different, and inevitably, the car was not fully optimized in terms of intake/exhaust and other aspects.

During the season, the team focused on aerodynamic upgrades, especially around the front wing and bargeboard, and many new parts were introduced. Although these updates showed results in aerodynamic improvements, the team was unable to take full advantage of the seven tire compounds (previously there were five), and good results were elusive.

The RA618H was an evolution of the newly developed RA617H with improved performance, and retained the basic concept and framework. However, many improvements and new parts were introduced to further evolve the unit. The most significant change was the reduction of intake and exhaust valve angles. This resulted in a more compact combustion chamber and a higher compression ratio. Improvements were made in numerous areas to improve reliability. Asaki, in charge of development, particularly focused on ensuring the reliability of the MGU-H, previously a weak point, and with the help of the HondaJet development team as an “all-Honda” effort, achieved remarkable progress.

For Honda, Round 7, Canada, became a major turning point. Red Bull, whose relationship with Renault had been deteriorating, previously informed Honda that it would make a decision by the end of the race on whether it would use Honda power units starting in 2019. Honda had introduced the Spec 2 engine in the Canadian GP. The engine, which featured a new combustion system, a revised exhaust system, and a new MGU-H, was the culmination of Honda’s efforts to secure a partnership with Red Bull. Although the race results were poor, the driving data showed performance that convinced Red Bull, and contributed to the team making great progress in building the partnership.

The Spec 3 engine introduced for Round 16, Russia, was a noteworthy evolution. A new combustion concept was adopted, resulting in a significant increase in power output. The new “fast combustion” system was the basis for the high performance demonstrated later in the season.

The season’s highlight was in Round 2, Bahrain. Pierre Gasly qualified 6th (5th on the grid) after entering Q3 for the first time in his career, and finished the race 4th, bringing a great deal of hope and expectations to the new team. This was, however, the best result of the season, and the team and Honda, which were still undergoing major changes and evolving, were unable to keep the momentum up, and race results remained poor.