The NTT INDYCAR SERIES will take the next step toward competing with hybrid technology when an oval test is held Tuesday at the Milwaukee Mile.

Twenty car-and-driver combinations will be on the historic 1-mile oval which will host the Hy-Vee Milwaukee Mile 250s on Aug. 31 and Sept. 1.

The hybrid technology will make its race debut in the Honda Indy 200 at Mid-Ohio presented by the 2025 Civic Hybrid on July 7 at the Mid-Ohio Sports Car Course in Lexington, Ohio.

INDYCAR, Chevrolet and Honda have collaborated to develop the first-of-its-kind hybrid unit. The 2.2-liter, twin-turbocharged V-6 engine was initially paired and tested with hybrid power in August 2023 at Sebring International Raceway. In just seven months, 23,518 miles have been successfully completed among 28 NTT INDYCAR SERIES drivers.

Tuesday will serve as the largest field for a hybrid test. Previous on-track hybrid testing has taken place at Barber Motorsports Park, the Homestead-Miami Speedway road course, Indianapolis Motor Speedway, the IMS road course, the Milwaukee Mile, Road America, Sebring and World Wide Technology Raceway to mirror the various disciplines of the NTT INDYCAR SERIES schedule.

The Milwaukee Mile will be hosting its first NTT INDYCAR SERIES race since 2015. Among drivers testing Tuesday, Ed Carpenter, Graham Rahal, Will Power, Josef Newgarden and Katherine Legge have series experience at the track. Jack Harvey has not competed in a series race at the track, but he finished fifth in the INDY NXT by Firestone race held there in 2014.

Chip Ganassi Racing and Juncos Hollinger Racing are not participating in this week’s test due to several of their drivers being in France for this weekend’s 24 Hours of Le Mans sports car race. Drivers who have not tested the hybrid at Milwaukee will get their chance during a session held later in the season.

The premise of Tuesday’s session will be to adapt to the hybrid with a customary test during the morning hours. In the afternoon, competitors will be allowed to simulate race conditions with group running and pit stops.

INDYCAR’s hybrid power expands the series’ efforts to deliver the most competitive motorsport on the planet. The new powerplant unit will feature additional overtake (Push to Pass) options, ultimately giving NTT INDYCAR SERIES drivers more choices and control, enhancing the on-track competition and excitement.

The innovative hybrid system is made up of the low voltage (48V) Motor Generator Unit (MGU) and Energy Storage System (ESS) – consisting of 20 ultracapacitors – both of which fit inside the bellhousing located between the Chevrolet and Honda INDYCAR SERIES internal combustion engine and the gearbox. During regeneration, acting on the clutch shaft, the MGU builds power to be stored in the ESS. The additional horsepower is deployed through the same motor generator on driver demand.

For competition, options for automatic “regen” via braking or throttle position and manual “regen” via selected steering wheel paddles and buttons will be available. Deployment of stored energy will only be available manually through a latching button, similar to the existing Push to Pass system.

While available to use in addition to the traditional INDYCAR Push to Pass system on road and street circuits, the two systems will come with different rules. Push to Pass will still have a restriction on the amount of time per use and total time used over the course of a race. Rules for the hybrid power unit will limit the amount of energy deployed per lap based on track length. Used in combination on road and street circuits, the additional boost will provide an additional 120 horsepower for a total of 800-plus horsepower for the first time in two decades. Additional horsepower is expected in the coming years as hybrid unit development evolves.

Safety elements include the low-voltage system and, on road and street circuits, the ability for drivers to restart the car themselves if they spin and stall the engine on the track. That reduces the need for the AMR INDYCAR Safety Team to be deployed resulting in more green-flag action.

The NTT INDYCAR SERIES returns to action Sunday, July 23 with the Firestone Grand Prix of Monterey at WeatherTech Raceway Laguna Seca (6 p.m. ET, USA Network, Peacock, INDYCAR Radio Network).