Now, for the rough stuff. After early tests on the smooth asphalt of the Indianapolis Motor Speedway road course and oval back in August and September, the new NTT IndyCar SERIES IR-28 chassis has faced its first true beating away from IMS.
Five-time and reigning NTT IndyCar SERIES champion Alex Palou of Honda-powered Chip Ganassi Racing completed 43 laps on Monday on the outer loop at Sebring International Raceway in Sebring, Florida. 2016 Indianapolis 500 winner Alexander Rossi of Chevrolet-powered ECR is scheduled to take over testing duties on Tuesday at the historic Florida circuit.
Sebring remains a favorite testing spot for NTT IndyCar SERIES teams because its bumpy nature and mix of asphalt and concrete surfaces closely simulate the temporary street circuits that made up a third of the 2026 schedule. It is a punishing, unforgiving track that stresses the durability and strength of components better than almost any other venue.
“We’re trying to test it as tough as we can,” Palou said. “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.”
Palou and Rossi are the only series drivers so far entrusted with testing the car, which is slated for introduction at the start of the 2028 season. Alongside Dallara and IndyCar officials, the drivers are working through a long checklist of basic system and performance checks.
Feedback from the initial IMS tests has already paid off. Palou noticed significant improvements in driver comfort and braking, particularly regarding driver cooling. Unlike the current car, which features cooling ducts added as an afterthought to the existing carbon fiber body alongside the revolutionary aeroscreen introduced in 2020, the new machine incorporates strategically placed ducts from its initial design.
“Yeah, it’s been so much better, the cooling, since we started a couple months ago,” Palou said. “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.”
Monday also brought a historic milestone for the IR-28: Palou executed the first-ever on-track pass for the new chassis when he overtook a current car driven by Kyle Kirkwood of Andretti Global. Kirkwood was conducting a tire test at the circuit alongside Scott McLaughlin of Team Penske for Firestone Firehawk tires.
“It wasn’t planned,” Palou said. “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.”
The wealth of existing data from the current car at Sebring allows teams to directly compare performance against the IR-28, and all systems remain a go for the development program.
“I’m very excited,” Palou said. “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.”
