Tost: You should have seen the smiling faces

Tost said in an interview with Motorsport Network, “It is a big difference, believe me. This starts already with a design of the car. In the past, we just got a power unit and suppliers said: Look, this is the power unit, with the pipes, with all the aggregates, just put it into your car."

“And now our designers are sitting together with the Honda engineers, they think 'OK, how can we create the oil tank, for example, in front of the engine, how to put it in a best possible way into the chassis'.

“Or the exhaust system. This is a big impact to the aerodynamics on the side of the car. Also, when you get the hot air from radiators to the back, how, where do you get it out?

“In former times, we just had to find the way from our side, and now we are discussing it together with Honda.”

Toro Rosso and their previous engine supplier Renault had an acrimonious partnership which disintegrated beyond repair last year, but attitudes have changed at the Faenza factory.

Tost revealed, “You should have seen the smiling faces of the engineers when they came back from dyno run with the gearbox and the power unit. d. “They said: Hey, we could change the mappings during the running."

“You know before we just got it, we got the mappings and everything was in a black box and we couldn’t do anything. Even if we said 'well, maybe this is better” or 'this is better', they said 'take it and that's it'.

“And now we have an impact. And we can say 'look, let's try this and this way, maybe we can get a performance advantage'.

“And this helped a lot both sides, and therefore for Toro Rosso it was absolutely the best to decide [on] this cooperation with Honda.”

The first Honda-powered Toro Rosso, the STR13, impressed during recent testing in Barcelona as the Japanese giant set out to make amends for three woeful years since they returned to F1.

But Tost and Toro Rosso are already one step ahead with an eye on 2019, “I am expecting a lot from next year’s car. Since nearly one month we are working on next year’s car, and we get more and more better ideas how to place the different parts of the power unit in the best possible way for the chassis.”