The 2028 IndyCar season marks a transformative moment for North America's premier open-wheel racing series, introducing a second-generation hybrid system that represents a significant leap forward from the inaugural energy recovery platform that debuted mid-season in 2024.
As the sport transitions to the new Dallara IR28 chassis, the hybrid architecture undergoes fundamental reimagining, with engineers and manufacturers targeting substantial performance gains while maintaining the reliability essential to competitive wheel-to-wheel racing.
IndyCar's first hybrid iteration, launched in July 2024, operates as a 60-volt system utilizing supercapacitors for energy storage—a choice dictated by the spatial constraints of retrofitting an energy recovery system into the 15-year-old DW12 chassis.
The initial energy storage system incorporates 20 ultracapacitors produced by Skeleton Technologies, delivering an additional 60 horsepower on deployment with a five-second duration per charge cycle. This first-generation solution, despite its limitations, provided valuable operational data that now informs the development of Version 2, destined for integration into the IR28 platform.
The fundamental architecture of the hybrid system comprises the Motor Generator Unit (MGU) and the Energy Storage System (ESS), both housed within the bellhousing—the structural bridge located between the internal combustion engine and gearbox.
The MGU, manufactured by Empel Systems in collaboration with Chevrolet and Ilmor Engineering, captures kinetic energy during braking by converting it into electricity. This harvested energy flows to the ESS, where it remains stored until drivers activate deployment through a steering wheel button, supplementing engine output with additional power delivered to the driveshaft.
Mark Sibla, IndyCar's Senior Vice President of Competition and Operations, provided detailed insight into the evolution underway. The forthcoming Version 2 system maintains the 60-volt-or-less electrical architecture but represents a qualitative departure in energy storage capacity.
Where Version 1 permits deployment for approximately five seconds per charge, the enhanced system targets duration exceeding ten seconds—a doubling that would expand tactical opportunities for both offensive passing and defensive maneuvering across all track types.
The strategic advantages of extended deployment duration compound when paired with horsepower improvements. IndyCar currently pursues doubling the peak energy recovery system power to 120 horsepower, a substantial increase from the existing 60 horsepower output.
This elevation becomes feasible because the current MGU, designed by Empel, possesses capability approaching 100 to 150 horsepower under optimal conditions—a capacity constrained exclusively by the energy storage system's limited charge capacity in Version 1. As Sibla explained, enhanced energy storage technologies now permit simultaneous growth in both power output and deployment duration, eliminating the zero-sum engineering compromise that characterized the inaugural hybrid platform.
Two leading suppliers have advanced distinct but substantially similar energy storage solutions for Version 2 consideration. Both proposals offer reduced weight compared to current systems while achieving the mandated capacity expansion.
Sibla indicated the series would select one vendor partner following detailed technical evaluation, after which prototype development would accelerate toward late spring 2025 availability for initial testing with the IR28 chassis.
The decision to retain supercapacitor technology rather than transition to lithium-ion batteries reflects practical engineering calculus. Supercapacitors deliver superior charge and discharge velocity—critical for capturing braking energy and deploying power on demand—while occupying less physical space within the bellhousing structure.
Lithium-ion battery systems, though offering higher energy density, require substantially greater volume and weight to achieve comparable performance specifications, constraints incompatible with the designated installation envelope within Dallara's new chassis architecture.
One significant operational consideration under evaluation concerns the future role of traditional push-to-pass boost systems. Currently, IndyCar permits drivers two distinct power augmentation methods: the hybrid system, available at every race, and push-to-pass turbo enhancement, deployed on road courses and street circuits.
The series is examining whether Version 2 hybrid capabilities might supersede push-to-pass entirely, consolidating driver power management into a single deployment system. Such a transition would simplify cockpit control complexity while potentially altering strategic racing dynamics, though IndyCar has reached no definitive conclusion regarding this architectural change.
The integration timeline for Version 2 prototypes aligns with the broader IR28 chassis development schedule. Vendors submitted solution proposals to IndyCar, which then selected the most promising concepts for advancement.
Following vendor selection, prototype assembly targets late spring 2025, allowing parallel testing with the new chassis architecture to validate weight distribution, power delivery integration, and overall system synchronization across multiple evaluation sessions. This phased approach ensures accurate performance characterization before competitive deployment in 2028.
The broader powertrain context underscores the hybrid system's strategic importance within IndyCar's future development trajectory. The accompanying 2.4-liter twin-turbocharged V6 internal combustion engine, scheduled to debut alongside the IR28 platform, continues established technology from the 2.2-liter architecture that has powered the series since 2012.
The new engine represents evolutionary rather than revolutionary engineering, generating approximately 800 horsepower in naturally aspirated form. Combined with 100 additional horsepower from the hybrid system, the complete 2028 powertrain package approaches 900 horsepower—roughly 100 horsepower beyond the 2025 configuration, with headroom for continued growth into the 2030s.
This strategic emphasis on hybrid technology advancement, rather than continued combustion engine development, reflects broader automotive industry trends. As manufacturers increasingly prioritize electrification and efficiency, IndyCar's direction targets technological relevance for road car manufacturers evaluating racing participation.
Continued substantial investment in conventional piston engine development provides diminishing returns in an industry fundamentally reorienting toward hybrid and electric propulsion. Version 2 development therefore positions the series as a competitive proving ground for emerging energy storage and motor technologies applicable across the automotive sector.
The installation location of hybrid components—within the bellhousing cavity—derives from pragmatic necessity rather than optimal packaging design. Originally intended to accommodate a single turbocharger during Honda's 2012-2013 single-turbo program, this space sat vacant after IndyCar standardized twin-turbo configurations in 2014.
The hybrid project inherited this existing cavity, avoiding extensive chassis redesign while introducing packaging constraints that influenced early system specifications. The IR28 platform's development process has addressed these limitations more comprehensively, with engineers designing the bellhousing structure from inception to accommodate evolving hybrid architectures rather than retrofitting technology into legacy spaces.
Reliability and performance homogeneity across the full 28-car competitive grid represent non-negotiable requirements for any hybrid system evolution. Version 1's development partnership between Chevrolet, Honda, Ilmor Engineering, and IndyCar demonstrated the complexity of delivering identical performance characteristics to multiple teams operating under the financial and technical constraints inherent to professional racing.
Each vehicle must function with equivalent power output and deployment characteristics, eliminating relative advantage derived from equipment variance. This homologation requirement significantly constrains vendor freedom compared to road car development, where manufacturers pursue differentiated solutions. Vendors selected for Version 2 development therefore inherit responsibility for not merely advancing performance metrics but ensuring production-specification reliability and performance consistency across full-season racing programs.
The supercapacitor technology selection again underscores practical engineering priorities. Skeleton Technologies' 20-unit ultracapacitor packs deliver rapid charge and discharge cycles—essential for frequent regeneration on short ovals and street circuits where braking events occur multiple times per lap.
This characteristic advantage over battery-based systems persists despite battery technology evolution, as the inherent chemical kinetics of lithium-ion cells cannot match capacitor discharge rates for sustained high-power applications. The cost differential between supercapacitor and battery solutions, though not explicitly stated in IndyCar communications, likely played a secondary but meaningful role in vendor selection, particularly given team owner resistance to substantial powertrain cost increases.
The energy recovery system functions through driver-controlled regeneration strategies, either fully manual through steering wheel paddle modulation or semi-automatic through engine control unit programming that initiates regeneration at predetermined throttle or brake pressure thresholds.
Energy harvesting occurs during braking events on road and street courses, where heat typically dissipates uselessly, and during drafting scenarios on oval tracks where drivers lift throttle approaching lead vehicles. Once stored in the ESS, drivers manually deploy accumulated energy via steering wheel button activation, with the MGU translating electrical energy into mechanical power delivered to the engine driveshaft.
The parallel introduction of substantially lighter chassis components contributes equally to the 2028 competitive product enhancement. The IR28 design incorporates 85 to 100 pounds of weight reduction compared to current specifications, with the transmission alone accounting for approximately 25 pounds through advanced materials and design optimization.
This weight reduction, distributed across the chassis structure, improves power-to-weight ratios and handling characteristics independent of hybrid system contributions. The combination of lighter platform architecture and enhanced hybrid performance compounds to create a measurably more dynamic racing vehicle, potentially reducing lap times and elevating overtaking frequency across all track configurations.
IndyCar's transition to second-generation hybrid technology for 2028 therefore represents far more than incremental performance tuning. The comprehensive system evolution—encompassing extended energy storage duration, elevated power output, refined component integration, and supporting chassis lightweighting—reflects the series' commitment to technological relevance within rapidly evolving automotive landscapes.
As manufacturers increasingly evaluate racing series for validation of electrification and efficiency technologies, IndyCar's hybrid platform development positions the championship as a meaningful R&D laboratory rather than a legacy spectacle powered by aging combustion engine architectures. The 2028 season will reveal whether this technological investment translates to substantially improved racing product for competitors and spectators alike.
