As revealed by Motorsport.com earlier, F1 teams have been asking the FIA to conduct a more thorough analysis of the impact of the new 2026 cars and engines amid concerns about how they will perform on track.
There are worries that plans for increased reliance on batteries – with a 50/50 split between combustion engine and electric power production – could backfire and leave cars unable to run flat out around a lap because they cannot produce enough energy.
While the FIA is confident that the situation is under control and it is premature to be worried about matters, Horner has said that F1 needs to be careful with what happens – as he suggests it may be better to reduce the reliance on electrical power.
"I think that perhaps where we need to pay urgent attention before it's too late is to look at the ratio between combustion power and electrical power," he said at the Austrian Grand Prix.
"[We need] to ensure that we're not creating a technical Frankenstein, which will require the chassis to compensate to such a degree with moveable aero and reduce the drag to such a level that the racing will be affected – and that there will be no tow effect and no DRS because effectively you're running like that at all points in time.
"Plus, with the characteristics of these engines, that the combustion engine just doesn't become a generator to recharge a battery."
Horner does not believe the matter is complicated to solve, as he suggests a simple five per cent shift in combustion/electric power could be enough to help. However, he says the matter is a critically important one to get right.
"We still have two and a half years, and I think if there is a slight redress it would then create potentially a better platform for the chassis," he said.
"Otherwise, the chassis regs that are undefined yet and uncommitted, we're going to be trying to cater for those compromises.
"You have got to look at the thing holistically from both the technical point of view, and most importantly what is F1.
"F1 needs to be wheel-to-wheel racing. We can't afford to lose that challenge and have drivers downshifting on the straights to regenerate batteries.
"I know the FIA taking it very seriously, and they're looking at it very closely as the simulations become more advanced. "
Alfa Romeo team principal Alessandro Alunni Bravi said the 2026 engine regulations were a good thing for F1, as they had helped bring in the Audi company that is taking over his squad.
However, he agreed that there was scope to find improvements when it came time to fine-tuning the power unit rules alongside the chassis requirements.
"I agree that, of course, we can always improve, because it's important to keep the DNA of F1," he said.
"For Audi it has been important, this new regulation, and it has been the factor that pushed them to enter into F1, and I think it is important too, for everybody and all the stakeholders, that Audi will enter, and that we are attractive for new manufacturers.
"The focus on sustainability is crucial for the car manufacturers, and all the stakeholders are working to have a good show and to have a good car.
"Then the matter of ratio? It is difficult to say, but what Christian said, I agree that we need to have a holistic approach. It is not just a matter of PU, it is a matter of the overall package, the chassis and the engines."
Horner said that another issue that needed to be factored into the evaluation of the 2026 rules was the extra weight of the batteries, which he has described as "colossal."
"One of the big impacts for 2026 is weight," he said. "You're looking at pretty much a 30-kilogramme swing, on cars that are already approaching the sort of sportscar type of weight through the cooling."
