Chevrolet has confirmed that none of the problems that caused four of its cars to retire from Sunday’s NTT IndyCar Series race at Mid-Ohio were related, although Chevy’s IndyCar program manager Rob Buckner says the Bowtie has some work to do to tighten up reliability ahead of a packed July schedule.

“It was a surprising messy day,” Buckner told RACER. “The odd thing to me was that we ran Friday and Saturday pretty much flawlessly, and then it seemed like the race started and it was just continuous issues. I guess the good and bad news is that each car that had problems was unique, so it’s not like we had a rash of failures at a certain mileage. All of these engines were due to come out after Mid-Ohio, so they were all in that 2000 mile and up range, so initially you start thinking, ‘oh, do we have some major issue around the 2000 mile mark?’, but they were all pretty unique.”

The two most consequential problems eliminated the pair of Arrow McLaren SP cars, with Felix Rosenqvist’s No.7 coming to a smoky halt after just eight laps, and Pato O’Ward’s No.5 developing the first signs of what became terminal problems while the Mexican was holding a comfortable lead towards the end of the first stint.

“The No.5 car was a fuel supply issue,” said Buckner. “That engine had been repaired from a Chevy issue at Road America, but what happened on Sunday was just fuel supply, outside of Chevy’s control, and really outside of the team’s, also. The fuel system has some required suppliers and parts, so that one was just an un fortunate incident. It was extra-painful because that car was on track for a very good day.

“The No.7 was something totally different; definitely on our side. It was a quick engine failure. We don’t have that one root-caused yet; we need to get it apart this week and see what failed. We take a lot of pride in not having on-track engine failures and Felix was having a good day, so we let him and the No.7 team down. So definitely we need to do better for Arrow McLaren SP. We take a lot of pride in having reliable race engines, and Pato was a DNF at Road America that was on us, and Felix was a DNF on us at Mid-Ohio, and the No.5 car also had its issue. So we’re having a rash of reliability concerns with AMSP that we’re going to do everything we can to address, and we know the race team will do the same. We’re looking forward to getting to Toronto and moving on with that group.”

According to Buckner, the recent streak of problems affecting AMSP have not been related to anything specific to the team and how it works with the engines.

“They’ve just been unlucky,” he said. “Pato’s issue at Road America was an electrical sensor failure that could have happened to any one of our cars. And then the mechanical failure we saw with Felix, we don’t know what the root cause of that was yet but those are always quite random. We work very hard to avoid those. We always respond well to these types of issues really quickly, so we’ll get on top of it and move on from here.”

Outside of AMSP, the No.11 A.J. Foyt Racing entry driven by Tatiana Calderon and Callum Ilott’s No.77 Juncos Holinger Racing car also dropped out early.

“The No.11 car had a shifting issue that was team-side that ended their day prematurely, and then the No.77 car was an odd engine event that led to an engine failure and retirement,” Buckner said. “So we ended up with four cars retiring with driveline issues, which is way too many. I was a pretty long day.

“But at the same time, we left with the trophy, so if you have a bad day and can still leave with a victory, I think everyone in our camp will take that. We just need to clean up a few loose ends before we get into these next four race weekends in July and kind of hit the reset button leaving Mid-Ohio.”

Despite the unusually high tally of mechanical failures, Chevrolet ended the weekend with three of its cars in the top four, spearheaded by Team Penske’s race-winner Scott McLaughlin. Buckner said that the performance across the Chevy teams was the silver lining from a frustrating race.

“I’m really proud of our group,” he said. “We never quit, which is a good thing because right now we have some issues we need to fix! It was odd, Friday and Saturday at Mid-Ohio being pretty calm, and then all of a sudden the green flag flies for the race and it’s just chaos from the beginning.

“But to still be able to win speaks volumes to the depth we have right now. If we can clean up our reliability for performance improvement, our teams and drivers are doing a great job. I’m really proud of McLaughlin; both races he’s won this year he’s held off (Alex) Palou. Will Power’s drive from the back to the front was huge for the championship, and Josef Newgarden’s right there, too. If it wasn’t for his qualifying issue… we hate to be greedy, but if you look at the pace we had, we should have had a better weekend than we did.

“So I think we still have a lot of potential to have a good second half of the season. We just need to keep pushing because we know clearly how quickly events can turn on you. Five races in July; we need to close out all these issues and get back to business.”

Chevrolet’s one-three finish at Mid-Ohio gives it an 81-point lead over Honda in the manufacturers’ championship going into next weekend’s race in Toronto.