Five-time and reigning NTT INDYCAR SERIES champion Alex Palou completed 43 laps on Monday at Sebring International Raceway, pushing the new IR-28 chassis through its first rigorous track test outside of Indianapolis Motor Speedway, INDYCAR.com reported. Honda-powered Chip Ganassi Racing fielded Palou for the outing on the circuit’s punishing outer loop, which replicates the high-degradation surface profile of temporary street circuits.
The Sebring Stress Test and Component Durability
Initial development runs for the IR-28 chassis took place in August and September on the billiard-table smooth asphalt of the Indianapolis Motor Speedway road course and oval. Monday’s session at Sebring International Raceway provided a stark contrast, offering an unforgiving testing ground that stresses structural integrity and component longevity better than any other venue on the calendar. INDYCAR.com reported that series teams frequently utilize the Florida circuit to simulate the demanding bumps of street circuits, which accounted for a third of the 2026 schedule.
“We’re trying to test it as tough as we can,” Palou said, according to INDYCAR.com. “It’s a bumpy course. Before we produce all the new cars, we want to make sure it passes this stress test and that it’s good to go for racing. We’re trying to get miles and miles, see what breaks so we can fix it.”
| Session Details | Parameter | Operational Focus |
|---|---|---|
| August – September 2026 | IMS Road Course & Oval | Baseline performance and system checks |
| Monday | Sebring Outer Loop | Durability, component stress, and traffic simulation |
| Tuesday | Sebring International Raceway | Continuation of testing by Alexander Rossi |
Cockpit Improvements and On-Track Traffic Dynamics
Feedback from the initial IMS tests directly influenced design iterations evaluated during the Sebring run. Palou noted that driver comfort and braking feedback yielded notable enhancements, particularly regarding thermal management within the cockpit. The current generation of cars relies on carbon fiber body modifications added after the 2020 introduction of the aeroscreen. By contrast, the IR-28 incorporates strategically positioned ducting from the initial design phase.
“Yeah, it’s been so much better, the cooling, since we started a couple months ago,” Palou said, as reported by INDYCAR.com. “Huge step, and that’s something we’ve been asking for a long time on our current car. We have a very big one right in front of us that makes the air go from down to up and makes the airflow so much better. It’s been huge.”
The test session also produced a milestone when Palou completed the first unofficial on-track pass in the IR-28, overtaking a current-specification car driven by Andretti Global’s Kyle Kirkwood. Kirkwood and Team Penske’s Scott McLaughlin were conducting concurrent Firestone Firehawk tire evaluations at the facility.
“It wasn’t planned,” Palou said, according to INDYCAR.com. “We went out, and I saw Kirkwood was doing the tire test. We spoke during lunch that at some point this afternoon we would go together. We wanted to see how this car does in traffic. It was cool. We were playing a little bit.”
Upcoming Evaluation Schedule and Development Timeline
Testing duties at Sebring rotate on Tuesday, with 2016 Indianapolis 500 winner Alexander Rossi stepping into the cockpit for Chevrolet-powered Arrow McLaren partner team entries, though INDYCAR.com noted Rossi represents ECR for this test assignment. Dallara engineers and series officials continue to methodically clear a long checklist of basic system evaluations before the chassis is manufactured at scale for the 2028 campaign.
“I’m very excited,” Palou said, as detailed by INDYCAR.com. “I like the looks of it. It seems safer. It looks like it’s going to be much better racing because we’re going to be able to follow much closer on road, street and ovals. I’m just excited to go racing. I wish it was already ’27. Having said that, it gives us so much time to work on the car, to make sure it’s good. If there’s something that doesn’t really work on ovals or whatever, we can go test it before we actually race it.”
