IndyCar will dial back the power of its hybrid system for this weekend's race at Road America, reverting to a lower energy limit in an effort to stem a run of reliability failures that has frustrated drivers and squeezed the supply of spare units.
The lap energy limit at Road America drops from the 600 kilojoules used last year to 535 kJ this weekend — a return to the "validated electricity flow average" first introduced when the hybrid era began in 2024.
IndyCar confirmed the change in a statement, framing it as a supply-and-durability measure recommended by the unit's manufacturer.
"As part of IndyCar's evaluation of hybrid power unit supply, a recommendation was made by the Energy Storage System (ESS) manufacturer, to reduce the lap energy limit," the series said. "After review, IndyCar is reverting to the validated electricity flow average as introduced in 2024 and for the start of the 2025 season for this weekend's event at Road America."
"The move is aimed to help reduce thermal load and aging of the ESS cells, which will help with robustness of the hybrid power unit, stabilize system fallout and assist with unit supply. Following this weekend's event, IndyCar will re-evaluate the update to determine additional implementation this season."
The decision follows a wave of hybrid failures across the first nine races of 2026 that forced so many replacements it triggered concerns about whether enough spare units would last the summer. Ahead of the Bommarito 500 a fortnight ago, IndyCar said a two-week break before Road America would give suppliers time to build the stock needed "towards the finish of the 2026 championship."
The ESS — made up of 20 supercapacitors — stores energy that is deployed by a low-voltage motor generator unit and then regenerated under braking. When it fails, the consequences vary: some cars lose only the hybrid boost, while others suffer a complete engine shutdown.
That was Scott Dixon's experience at the Detroit Grand Prix on May 31, when the six-time champion hit a hybrid problem inside the first 10 laps. His Chip Ganassi Honda soldiered on until lap 69 before the engine cut out, leaving him 24th.
Alexander Rossi has been among the most pointed critics of a system the grid never asked for.
"I mean, it's pretty annoying to have a failure in the car because of a product that we didn't ask for that doesn't improve the racing," Rossi said. "So that's frustrating."
The timing of the cut is awkward. Road America's Grand Prix falls on the first day of summer, and rising temperatures load extra thermal stress onto the 2.2-litre, twin-turbocharged V6 engines, which already run under heavy heat. Reducing deployment is intended to ease that strain on the cells.
It is a stopgap rather than a cure. The hybrid is in only its second season, bolted between engine and transmission, and IndyCar is wrestling with its reliability in the penultimate year of the current Dallara DW12 chassis. Whether the lower energy limit proves a lasting fix or simply buys time until a deeper redesign will become clearer once the series reviews the data after Road America.
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*Originally published on [Motorsports](https://motorsports.global/article/indycar-cuts-hybrid-power-at-road-america-to-curb-failures). Visit for full coverage.*