Horner has been active in F1 Commission and team principal meetings in suggesting that grand prix racing’s bosses need a rethink over plans for the 2026 cars.
In particular, he is concerned that engines running out of power on straights because batteries are not powerful enough, allied to cars that cannot compensate in performance terms, could hurt the show.
He is clear that, if the FIA does not get the chassis regulations spot on in working with the engines, then there is a risk of creating ‘Frankenstein’ cars.
But Horner’s stance has drawn scepticism from Mercedes boss Toto Wolff, who suggested that the complaints are being fuelled for selfish competitive reasons.
Wolff said: “I think what frightens him more maybe is that his engine programme is not coming along, and then maybe he wants to kill it [the rules] that way.
"So, you always have to question what's the real motivation to say something like that."
But Horner is far from impressed by what Wolff says, and has made it clear that his priority is in ensuring that F1 does not get things wrong as it finalises the 2026 rules package.
“Unfortunately, that's typically Toto, where he's just focused on self-performance,” said Horner, when asked about the remarks. "My interest is actually about the sport rather than self-gain.
“It is still way too early to say who's going to have a competitive or uncompetitive engine in 2026. For me, the most important thing is, from a sports point of view, that we all have a collective responsibility to work with the FIA and the commercial rights holder, to ensure that the product is as good as it can be. Otherwise, we've all failed.”
Autosport understands that early simulation of the 2026 engines shows that if it ran in the back of current cars, which have high drag levels, then there would be a few events where power would become a problem.
However, the FIA is confident that the work it is doing on developing active aero to reduce drag on straights will ensure there are no such issues when the cars appear for real.
Horner thinks it is important he speaks up because issues have cropped up as teams have come to better understand the implications of the new rules set.
“The regulations are a hybrid of what was originally intended,” added Horner. “Of course, it's only as you work through a set of regulations that you find out where their limitations are.
“I think the FIA are being very responsible in terms of doing their due diligence. And, I think, certain teams share very similar opinions on that.”
Asked by Autosport if he had faith that the FIA was taking the matter seriously enough, Horner said: “Yes. I think so. I think they have a capable team and that they're aware of what the challenges are.
“You have heard recently the [FIA] president's comment about weight. Now, that's not an easy thing to reduce, when you look at the increase in cell size that we have and the cooling that obviously goes with that.”
