Former Formula 1 driver and paddock analyst Johnny Herbert has voiced concerns about the reliability of Mercedes power units as teams prepare for the sweeping 2026 technical regulations. The three-time Grand Prix winner claims to have heard troubling reports from inside the sport’s development programmes, suggesting the German manufacturer may not hold the anticipated advantage when the new era begins.
Reports emerge of Mercedes power unit failures during testing
Herbert revealed he has received information about significant technical difficulties at Mercedes’ High Performance Powertrains facility in Brixworth. Speaking candidly about the pre-season development phase, the British racing veteran indicated that initial attempts to install the new-specification power units into test mules resulted in the cars failing to start.
The revelation contradicts earlier speculation within the paddock that Mercedes had established itself as the frontrunner for the 2026 regulatory cycle. After months of rumours positioning the Silver Arrows as best-prepared for the radical rule changes, these reported setbacks paint a different picture of the manufacturer’s readiness.
Herbert acknowledged the inherent challenges of any major technical overhaul. “There will be many small problems, as always with a new year featuring a new car and new rules,” he noted. The distinction between controlled factory testing and real-world circuit conditions often exposes unforeseen complications that even the most sophisticated simulation programmes cannot predict.
Battery management emerges as critical challenge for 2026
The 2026 regulations represent the most significant shift in Formula 1’s hybrid era, with a near-equal split between internal combustion engine output and electrical power. This fundamental change places unprecedented emphasis on energy deployment strategies and battery efficiency throughout race distances.
Herbert highlighted that simulator work has already identified battery depletion as the primary technical hurdle teams must overcome. The removal of the MGU-H component, which previously harvested energy from exhaust gases, eliminates a crucial energy recovery system that has underpinned the current power unit architecture since 2014.
Teams have reportedly begun recruiting specialist engineers from Formula E, where battery management expertise has been refined over a decade of all-electric racing. These engineers bring sophisticated software configuration knowledge that could prove decisive in maximising electrical deployment without compromising race pace.
The introduction of active aerodynamics adds another layer of complexity. Drivers and race engineers will need to balance drag reduction for straight-line speed against the electrical energy required to power these systems, creating a multi-dimensional strategic puzzle that could dramatically alter racing dynamics.
McLaren‘s benchmark status faces uncertain future
The reigning constructors’ champions enter the regulation change from a position of strength, but Herbert cautioned against assuming McLaren will maintain its competitive advantage. The Woking-based team’s dominance during the 2024 season was built on aerodynamic efficiency and mechanical grip under the current technical framework—attributes that may not translate directly to the 2026 specifications.
The former Stewart and Jaguar driver emphasised how drastically different the engineering priorities will become. Active aerodynamic components, the absence of MGU-H technology, and the fundamental shift in power unit philosophy mean teams are essentially starting from a blank canvas. Historical performance data and accumulated knowledge from the current generation will have limited applicability.
McLaren’s recent success stemmed from incremental refinement of the existing regulations, exploiting marginal gains in floor design and rear suspension kinematics. The 2026 reset eliminates these hard-won advantages, potentially reshuffling the competitive order in ways that mirror the upheaval seen during previous regulatory revolutions in 2009, 2014, and 2022.
Cadillac faces steep learning curve as new entrant
Herbert predicted that the American manufacturer’s entry will likely encounter significant growing pains during its inaugural seasons. Despite securing experienced drivers including Valtteri Bottas and Sergio Pérez, the former Jordan driver believes Cadillac will struggle at the back of the grid initially.
Drawing from his own experience with new teams, Herbert suggested a realistic timeline of four to five years before Cadillac reaches full competitive maturity. Establishing the technical infrastructure, recruiting specialist personnel, and developing the institutional knowledge required to compete at Formula 1’s highest level cannot be rushed, regardless of financial backing.
The challenge extends beyond simply designing and building a competitive car. Teams must develop sophisticated simulation tools, establish effective communication protocols between trackside and factory operations, and cultivate the operational excellence that separates midfield runners from championship contenders. These intangible elements typically require multiple seasons to refine.
What this means going forward
The 2026 season promises to be one of the most unpredictable in recent Formula 1 history, with technical regulations that fundamentally alter the sport’s engineering philosophy. Herbert’s warnings about Mercedes’ early struggles and the emphasis on battery efficiency suggest the competitive order could look dramatically different from the current landscape.
Teams that successfully integrate Formula E engineering expertise and master the complex interplay between electrical deployment and active aerodynamics may establish early advantages that prove difficult to overcome. The removal of MGU-H technology levels the playing field in unexpected ways, potentially allowing smaller manufacturers to compete more effectively against established power unit suppliers.
For Cadillac, patience will be essential. The luxury manufacturer’s long-term commitment to Formula 1 must account for an extended development phase before meaningful results emerge. Meanwhile, the established teams face their own uncertainty as they navigate the most significant technical challenge since the hybrid era began over a decade ago.
