Four-time Formula 1 champion Sebastian Vettel has voiced concerns over the sport's next big rule change. The former Red Bull driver has cautioned that the upcoming regulations might undermine what makes F1 the pinnacle of motorsports.Speaking to the German outlet Auto Motor und Sport, Vettel discussed the 2026 F1 regulations. While he supports the push towards greener technology, the changes must not come at the cost of the core spirit of racing."From a sporting perspective, the competition must be as close as possible without damaging the spirit of Formula 1. And people must also be able to afford the sport," Vettel said.At present, teams are deep into preparations for the new rules, even with 10 races left in 2025. Most have admitted their focus is already fixed on 2026, with limited updates expected on current cars until the end of the season.The new era will see lighter, more agile cars, around 30kg slimmer, designed to improve on-track battles. The power unit will be overhauled, with a 50-50 split between internal combustion and electric power, running on 100% sustainable fuels.Cars will feature active aerodynamics, with moveable front and rear wings replacing the current Drag Reduction System. A new 'push-to-pass' style function will also give drivers a short burst of extra battery power when within a second of the car ahead.On paper, these measures are aimed at producing closer, more exciting races. But Sebastian Vettel believes the improvements fall short. He welcomed the move to climate-neutral fuels but urged caution."I think climate-neutral fuels are good because there's a need for them outside motorsport... for cars already on the road, for shipping, for aircraft... if you unleash the development race typical of Formula 1 on them, things can quickly go in the wrong direction, as was the case in 2014... We're moving a little in that direction now, but it's just a drop in the ocean. The cars are far too heavy. They should actually be 200 kilograms lighter," he warned.The 2014 F1 regulations made the switch to 1.6-liter V6 hybrid engines from V8s. The changes were made with a focus on sustainability and road car relevance. But it led to widespread criticism about the diminished racing experience.While Sebastian Vettel maintains sustainability matters, so does keeping racing affordable and relevant."The new regulations aren't entirely convincing": Sebastian Vettel's verdict on the 2026 F1 carSebastian Vettel during the 2024 Formula 1 Grand Prix of Brazil. Source: GettySebastian Vettel admits it is too early to know the full impact of the 2026 F1 regulations until the 2026 testing sessions. The first proper test of the 2026 cars begins at the Circuit de Barcelona-Catalunya on January 26, followed by two sessions in Bahrain.Only after teams participate in these sessions can a conclusion be drawn about the car and its qualities. For now, he remains unconvinced."The new regulations aren't entirely convincing to me yet," he added (via Auto Motor und Sport)Vettel also highlighted a wider issue of balancing innovation and entertainment. In his view, F1 has unique demands compared to other motorsports like the 24 Hours of Le Mans or Formula E, and a fully electric path doesn't suit the sport. He pointed to the thrill of the V10 era, where the sound of the engines was part of the spectacle."I was able to experience what a V10 feels and sounds like. And that's part of the show and the Formula 1 experience. Back then, you didn't just go to the racetrack to see who would win. You also wanted to breathe in the whole fascination around it."That connection may not be as strong for younger fans who grew up in the hybrid era, but Sebastian Vettel believes F1 must still preserve its sense of wonder. Current drivers who have tested early simulator versions of the 2026 cars have described them as 'not enjoyable' and 'a bit sad', underlining that skepticism exists across the grid.