Honda's progress during their first pre-season test with two teams since returning to Formul1 has been "seamless" according to Toro Rosso technical boss Jody Egginton. The Japanese marque has added Red Bull as a partner for 2019, having enjoyed a year of recovery with Toro Rosso in 2018.
With Red Bull having ditched long-term suppliers Renault after 12 years – four of them championship-winning – many eyes were on their efforts at the first pre-season test in Barcelona last week.
However, any fears of the reliability issues which dogged McLaren in three years with Honda were swiftly put to bed as the Red Bull squads combined for 957 laps of the Circuit de Catalunya.
Regular Red Bull claims of improved power were backed up by Egginton, who says taking on the strain of another team has done nothing to slow Honda's development.
"The engine programme has been fantastic," Egginton said, dismissing reports of a vibration issue that had reportedly prevented optimum running. "Honda have been working along on the background doing their thing. It's fantastic.
"They've been causing us no compromise, it's been great, the PU situation's been fantastic.
"We've sort of picked up where we left off at the end of last year. Plus we're familiar with their guys now, it's quite seamless for us, the majority of the guys in the garage are the same.
"So, from the Honda side, they're just getting on with it and we're leaving them to run their programme.
"Like every engine manufacturer Honda have been super busy over the winter, working on the next steps, and we're carefully validating what they've learned over the winter.
"We're introducing, step-by-step, these developments and pushing forward.
"Every team is nowhere near the edge of the operating window on the engine.
"Since this time last year the engine has taken a fantastic step forward. It was clear towards the end of last year that they'd made that step and they're just carrying on, so we're very happy in that respect."