Christian Horner continues to have nothing but praise for Red Bull's new works engine partner.

For others in the pitlane, a big question-mark hangs over the top-three team after switching from customer Renault to works Honda power for 2019.

'Like a Swiss watch'

But Horner, team boss, says Honda is helping Red Bull to "reduce the gap significantly" to Mercedes and Ferrari.

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"Of course you never know what the competition has done. If they've found 50kW more, then we have a big problem," he said.

But he thinks that is unlikely, given how impressed he has been by Honda's winter.

"We've never installed an engine as perfectly as this one. It looks like a Swiss watch under the bodywork," said Horner.

'Everything is new to us'

"We have four fresh and ready-to-use engines in the garage on the first day of a test. We have never had that," he added.

If Honda does have a weakness, it is reliability, but Horner insists that even if Red Bull does need to take a penalty, it is "not that great" on certain circuits.

Until then, he said Red Bull is still in the process of adjusting to its new constellation.

"Everything is new to us. Engine, regulations, drivers. First of all, we have to understand our package - the strengths, the weaknesses. 

"But we have not seen anything on the other cars that we have missed," said Horner.