Teams will be able to test Formula 1 cars that are one year old in 2026, according to reports.

      Formula 1 teams will be permitted to utilize one-year-old 2025 cars for their 'Testing of Previous Cars' (TPC) programs next year. Typically, TPC regulations stipulate that the single-seaters allowed to be tested on actual circuits, aimed particularly at aiding younger drivers, must be at least two years old. However, due to significant rule changes coming in 2026, the usage of 2025 cars on the test tracks will be allowed next year.

      According to Auto Motor und Sport, this could pose a challenge for teams that plan to switch engine suppliers in 2026. A prime example is Sauber, which is currently powered by Ferrari, but will transition to being the works Audi team with Audi engines starting in 2026. Journalist Michael Schmidt pointed out, "Ferrari is not particularly inclined to continue supplying Sauber with engines for the 2025 car, as Audi would then obtain a reference point and potentially gain too much insight from a rival's product." He added that even if Ferrari were to agree, the costs might be prohibitively high, with estimates ranging from $3-5 million per engine.

      Aston Martin is also changing its engine supplier for 2026, moving from customer Mercedes engines to works Hondas. However, Schmidt noted that they are undeterred by the associated costs, particularly since they are not counted against the budget cap. "Mercedes has only one condition," he explained. "Aston Martin must conduct its TPC program from a separate facility with an independent team, clearly differentiating itself from the operational group supplied with Honda engines."

      As for Alpine, which currently uses its own works Renault engines, the Enstone-based team will be switching to customer Mercedes engines for 2026. Schmidt added that a small team of Renault engineers would be available at Viry-Chatillon for the TPC tests to oversee the 2025 (Renault) power units before the 2026 Alpine-Mercedes engines can debut in 2028. He described the situation as "more challenging" for Red Bull, which will utilize its own engines in partnership with Ford next year as Honda transitions to Aston Martin. Team advisor Dr. Helmut Marko remarked, "There is an agreement with Honda for the future."

      In terms of the 2026 F1 tyres, there have been discussions in the Bahrain test paddock regarding the possibility of eliminating the new narrower dimensions of the Pirelli tyres. During the speculation, Max Verstappen was noncommittal when asked for his thoughts on the new development tyres, simply stating, "They’re round," with a smile. In contrast, Mercedes’ George Russell was more candid, asserting, "There’s no doubt they’re worse overall because they’re significantly narrower."

      According to Motorsport-magazin.com, Mercedes is particularly in favor of scrapping the narrower tyres and retaining the current sizes for the 2026 season. Despite this, the dimensions were initially developed in cooperation with the teams, who believed that the reduced drag and weight would be advantageous for the radically redesigned cars of 2026. Pirelli’s F1 chief Mario Isola commented on the situation, saying, "If the majority of teams wish to keep the current size, then we will accommodate that." He mentioned that Pirelli could easily use the existing moulds fitted with the 2026 compound mixtures.

      However, discarding the narrower tyres at this point seems unlikely, as various teams are believed to be well progressed with their designs for 2026 based on the original specifications.