Horner implied that he is more up to speed with what is happening at the new Red Bull Powertrains division, which he officially oversees and which is on the same site as the Red Bull race team in Milton Keynes.
He made the comments in the context of his warning that the 2026 regulations need to be changed to avoid the need for “Frankenstein” cars, and that the current balance between combustion engine and electrical power should be reviewed.
In response, Wolff has suggested that Horner is “frightened” because Red Bull is behind in its 2026 development programme.
Horner, in turn, has said that he believes the opposite is the case, and that RBPT has discovered the potential limitations of the new rules first because it is ahead of some rivals.
“I'm not sure how close Toto is to his engine business, because he's a customer, he’s not involved in HPP's business formally,” he said.
“The feedback that I'm getting from the business, and as you start to see the programme really coming to life and as the simulations firm up are some of the limitations. Which are inevitable.
“So I would say it's perhaps as a result of us maybe being well advanced that we're actually seeing some of the limitations.
"And I think that not for self-gain here as an engine manufacturer, just looking holistically at the whole lot, looking at the compromises that we're going to have to make on the chassis regs with fully active aero to compensate for the recovery on the engine, it still doesn't feel too late to tune that ratio.
“And it wouldn't take much. It's not like we're saying we have to rip everything up and start again. It's whether you do it on a fuel flow or the cell mass, you just need to change that ratio slightly to ensure that we get great racing.”
Red Bull's development will see the team join Ferrari as one of only two teams that creates its chassis and power unit on the same campus.
Regarding his own role at RBP, he said: “You’ve got to have a good team of people around you, and it's how efficient you are with your team.
"So for me, I've always been a big believer in giving responsibility and accountability to the people that you empower, because there's no point me telling them how to design an engine, I can't do that.
“What I can do is set the direction, set the targets and make sure they got the right facilities, the right infrastructure, the right support.
"So it's about having the right team and network around you, and how you then apportion and apply your time.”
Additional reporting by Jonathan Noble