Despite its improvements in 2018, Honda will need to make significant progress next season as it expands its efforts from one to two teams says motorsport boss Masashi Yamamoto.
In its first year of collaboration with Toro Rosso, after its split with McLaren at the end of 2017, Honda advanced both its performance and reliability this season.
The Japanese manufacturer's progress convinced Red Bull Racing to join forces with Honda for 2019, but Yamamoto is all too aware that its power unit is still no match for front-runners Mercedes and Ferrari, and that further improvements will be necessary.
"Over the course of the year, we improved our power unit in terms of performance and reliability, thanks to the huge efforts of our engineers and mechanics," Yamamoto was quoted as saying by Crash.net.
"Everyone at Scuderia Toro Rosso and both its drivers played a big part in our development, not just on the technical front, but also thanks to their open-minded and positive attitude and cheerful disposition. This was a great boost for all Honda members.
"We established a close and honest relationship, built on mutual respect and that produced some strong performances, such as those in Bahrain, Hungary and our qualifying in Suzuka. For this, our sincere thanks go to the entire team.
"However, it was clear that our PU is still not at the same level as the very best in terms of performance and there is also room for improvement when it comes to reliability."
Beyond Honda's engineering achievements, Yamamoto recently underlined the efficiency of its communication with Toro Rosso, something that had been a weak point of its collaboration with McLaren.
But adding a high-profile outfit such as Red Bull to its customers - a team that won't settle for anything less than outright wins - inevitably puts the manufacture with its back against the wall.
"Next season, we will supply two teams for the first time since we returned to F1 in 2015," added Yamamoto.
"We must do better and, with that in mind, everyone involved in the project is working relentlessly to be in good shape for pre-season testing in February.
"As we prepare for our second year with Toro Rosso and our first with Red Bull Racing, our aim is to continue to make progress and move up the order."